diff --git a/.circleci/config.yml b/.circleci/config.yml
index 80ec008153..6815bff85e 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -42,10 +42,13 @@ jobs:
   build_docs_pdf:
     working_directory: ~/bids-specification/pdf_build_src
     docker:
-      - image: danteev/texlive:TL2017
+      - image: danteev/texlive:latest
     steps:
       - checkout:
           path: ~/bids-specification
+      - run:
+          command: |
+            pip3 install numpy
       - run:
           name: generate pdf version docs
           command: sh build_pdf.sh
diff --git a/pdf_build_src/pandoc_script.py b/pdf_build_src/pandoc_script.py
index 1e3d18061c..b71607b94a 100644
--- a/pdf_build_src/pandoc_script.py
+++ b/pdf_build_src/pandoc_script.py
@@ -4,8 +4,7 @@
 """
 import os
 import subprocess
-
-
+           
 def build_pdf(filename):
     """Construct command with required pandoc flags and run using subprocess.
 
@@ -40,4 +39,4 @@ def build_pdf(filename):
 
 
 if __name__ == "__main__":
-    build_pdf('bids-spec.pdf')
\ No newline at end of file
+    build_pdf('bids-spec.pdf')
diff --git a/pdf_build_src/process_markdowns.py b/pdf_build_src/process_markdowns.py
index 23c9dd84f7..a4e6a870fd 100644
--- a/pdf_build_src/process_markdowns.py
+++ b/pdf_build_src/process_markdowns.py
@@ -1,191 +1,421 @@
-"""Process the markdown files.
-The purpose of the script is to create a duplicate src directory within which
-all of the markdown files are processed to match the specifications of building
-a pdf from multiple markdown files using the pandoc library (***add link to
-pandoc library documentation***) with pdf specific text rendering in mind as
-well.
-"""
-
-import os
-import subprocess
-import re
-from datetime import datetime
-
-
-def run_shell_cmd(command):
-    """Run shell/bash commands passed as a string using subprocess module."""
-    process = subprocess.Popen(command.split(), stdout=subprocess.PIPE,
-                               stderr=subprocess.PIPE)
-    output = process.stdout.read()
-
-    return output.decode('utf-8')
-
-
-def copy_src():
-    """Duplicate src directory to a new but temp directory named 'src_copy'."""
-    # source and target directories
-    src_path = "../src/"
-    target_path = "src_copy"
-
-    # make new directory
-    mkdir_cmd = "mkdir "+target_path
-    run_shell_cmd(mkdir_cmd)
-
-    # copy contents of src directory
-    copy_cmd = "cp -R "+src_path+" "+target_path
-    run_shell_cmd(copy_cmd)
-
-
-def copy_bids_logo():
-    """Copy BIDS_logo.jpg from the BIDS_logo dir in the root of the repo."""
-    run_shell_cmd("cp ../BIDS_logo/BIDS_logo.jpg src_copy/src/images/")
-
-
-def copy_images(root_path):
-    """Copy images.
-    Will be done from images directory of subdirectories to images directory
-    in the src directory
-    """
-    subdir_list = []
-
-    # walk through the src directory to find subdirectories named 'images'
-    # and copy contents to the 'images' directory in the duplicate src 
-    # directory
-    for root, dirs, files in os.walk(root_path):
-        if 'images' in dirs:
-            subdir_list.append(root)
-
-    for each in subdir_list:
-        if each != root_path:
-            run_shell_cmd("cp -R "+each+"/images"+" "+root_path+"/images/")
-
-
-def extract_header_string():
-    """Extract the latest release's version number and date from CHANGES.md."""
-    released_versions = []
-    run_shell_cmd("cp ../mkdocs.yml src_copy/")
-
-    with open(os.path.join(os.path.dirname(__file__), 'src_copy/mkdocs.yml'), 'r') as file:
-        data = file.readlines()
-
-    header_string = data[0].split(": ")[1]
-    
-    title = " ".join(header_string.split()[0:4])
-    version_number = header_string.split()[-1]
-    build_date = datetime.today().strftime('%Y-%m-%d')
-
-    return title, version_number, build_date
-
-
-def add_header():
-    """Add the header string extracted from changelog to header.tex file."""
-    title, version_number, build_date = extract_header_string()
-    header = " ".join([title, version_number, build_date])
-
-    # creating a header string with latest version number and date
-    header_string = ("\chead{ " + header + " }")
-
-    with open('header.tex', 'r') as file:
-        data = file.readlines()
-
-    # now change the last but 2nd line, note that you have to add a newline
-    data[-2] = header_string+'\n'
-
-    # re-write header.tex file with new header string
-    with open('header.tex', 'w') as file:
-        file.writelines(data)
-
-
-def remove_internal_links(root_path, link_type):
-    """Find and replace all cross and same markdown internal links.
-    The links will be replaced with plain text associated with it.
-    """
-    if link_type == 'cross':
-        # regex that matches cross markdown links within a file
-        # TODO: add more documentation explaining regex
-        primary_pattern = re.compile(r'\[((?!http).[\w\s.\(\)`*/–]+)\]\(((?!http).+(\.md|\.yml|\.md#[\w\-\w]+))\)')  # noqa: E501
-    elif link_type == 'same':
-        # regex that matches references sections within the same markdown
-        primary_pattern = re.compile(r'\[([\w\s.\(\)`*/–]+)\]\(([#\w\-._\w]+)\)')
-
-    for root, dirs, files in os.walk(root_path):
-        for file in files:
-            if file.endswith(".md"):
-                with open(os.path.join(root, file), 'r') as markdown:
-                    data = markdown.readlines()
-
-                for ind, line in enumerate(data):
-                    match = primary_pattern.search(line)
-
-                    if match:
-                        line = re.sub(primary_pattern,
-                                      match.group().split('](')[0][1:], line)
-
-                    data[ind] = line
-
-                with open(os.path.join(root, file), 'w') as markdown:
-                    markdown.writelines(data)
-
-
-def modify_changelog():
-    """Change first line of the changelog to markdown Heading 1.
-    This modification makes sure that in the pdf build, changelog is a new
-    chapter.
-    """
-    with open('src_copy/src/CHANGES.md', 'r') as file:
-        data = file.readlines()
-
-    data[0] = "# Changelog"
-
-    with open('src_copy/src/CHANGES.md', 'w') as file:
-        file.writelines(data)
-
-
-def edit_titlepage():
-    """Add title and version number of the specification to the titlepage."""
-    title, version_number, build_date = extract_header_string()
-
-    with open('cover.tex', 'r') as file:
-        data = file.readlines()
-
-    data[-1] = ("\\textsc{\large "+version_number+"}" +
-                "\\\\[0.5cm]" +
-                "{\large " +
-                build_date +
-                "}" +
-                "\\\\[2cm]" +
-                "\\vfill" +
-                "\\end{titlepage}")
-
-    with open('cover.tex', 'w') as file:
-        data = file.writelines(data)
-
-
-if __name__ == '__main__':
-
-    duplicated_src_dir_path = 'src_copy/src'
-
-    # Step 1: make a copy of the src directory in the current directory
-    copy_src()
-
-    # Step 2: copy BIDS_logo to images directory of the src_copy directory
-    copy_bids_logo()
-
-    # Step 3: copy images from subdirectories of src_copy directory
-    copy_images(duplicated_src_dir_path)
-    subprocess.call("mv src_copy/src/images/images/* src_copy/src/images/", 
-                    shell=True)
-
-    # Step 4: extract the latest version number, date and title
-    extract_header_string()
-    add_header()
-
-    edit_titlepage()
-
-    # Step 5: modify changelog to be a level 1 heading to facilitate section 
-    # separation
-    modify_changelog()
-
-    # Step 6: remove all internal links
-    remove_internal_links(duplicated_src_dir_path, 'cross')
-    remove_internal_links(duplicated_src_dir_path, 'same')
\ No newline at end of file
+"""Process the markdown files.
+The purpose of the script is to create a duplicate src directory within which
+all of the markdown files are processed to match the specifications of building
+a pdf from multiple markdown files using the pandoc library (***add link to
+pandoc library documentation***) with pdf specific text rendering in mind as
+well.
+"""
+
+import os
+import subprocess
+import re
+from datetime import datetime
+import numpy as np
+
+
+def run_shell_cmd(command):
+    """Run shell/bash commands passed as a string using subprocess module."""
+    process = subprocess.Popen(command.split(), stdout=subprocess.PIPE,
+                               stderr=subprocess.PIPE)
+    output = process.stdout.read()
+
+    return output.decode('utf-8')
+
+
+def copy_src():
+    """Duplicate src directory to a new but temp directory named 'src_copy'."""
+    # source and target directories
+    src_path = "../src/"
+    target_path = "src_copy"
+
+    # make new directory
+    mkdir_cmd = "mkdir "+target_path
+    run_shell_cmd(mkdir_cmd)
+
+    # copy contents of src directory
+    copy_cmd = "cp -R "+src_path+" "+target_path
+    run_shell_cmd(copy_cmd)
+
+
+def copy_bids_logo():
+    """Copy BIDS_logo.jpg from the BIDS_logo dir in the root of the repo."""
+    run_shell_cmd("cp ../BIDS_logo/BIDS_logo.jpg src_copy/src/images/")
+
+
+def copy_images(root_path):
+    """Copy images.
+    Will be done from images directory of subdirectories to images directory
+    in the src directory
+    """
+    subdir_list = []
+
+    # walk through the src directory to find subdirectories named 'images'
+    # and copy contents to the 'images' directory in the duplicate src 
+    # directory
+    for root, dirs, files in os.walk(root_path):
+        if 'images' in dirs:
+            subdir_list.append(root)
+
+    for each in subdir_list:
+        if each != root_path:
+            run_shell_cmd("cp -R "+each+"/images"+" "+root_path+"/images/")
+
+
+def extract_header_string():
+    """Extract the latest release's version number and date from CHANGES.md."""
+    released_versions = []
+    run_shell_cmd("cp ../mkdocs.yml src_copy/")
+
+    with open(os.path.join(os.path.dirname(__file__), 'src_copy/mkdocs.yml'), 'r') as file:
+        data = file.readlines()
+
+    header_string = data[0].split(": ")[1]
+    
+    title = " ".join(header_string.split()[0:4])
+    version_number = header_string.split()[-1]
+    build_date = datetime.today().strftime('%Y-%m-%d')
+
+    return title, version_number, build_date
+
+
+def add_header():
+    """Add the header string extracted from changelog to header.tex file."""
+    title, version_number, build_date = extract_header_string()
+    header = " ".join([title, version_number, build_date])
+
+    # creating a header string with latest version number and date
+    header_string = ("\chead{ " + header + " }")
+
+    with open('header.tex', 'r') as file:
+        data = file.readlines()
+
+    # now change the last but 2nd line, note that you have to add a newline
+    data[-2] = header_string+'\n'
+
+    # re-write header.tex file with new header string
+    with open('header.tex', 'w') as file:
+        file.writelines(data)
+
+
+def remove_internal_links(root_path, link_type):
+    """Find and replace all cross and same markdown internal links.
+    The links will be replaced with plain text associated with it.
+    """
+    if link_type == 'cross':
+        # regex that matches cross markdown links within a file
+        # TODO: add more documentation explaining regex
+        primary_pattern = re.compile(r'\[((?!http).[\w\s.\(\)`*/–]+)\]\(((?!http).+(\.md|\.yml|\.md#[\w\-\w]+))\)')  # noqa: E501
+    elif link_type == 'same':
+        # regex that matches references sections within the same markdown
+        primary_pattern = re.compile(r'\[([\w\s.\(\)`*/–]+)\]\(([#\w\-._\w]+)\)')
+
+    for root, dirs, files in os.walk(root_path):
+        for file in files:
+            if file.endswith(".md"):
+                with open(os.path.join(root, file), 'r') as markdown:
+                    data = markdown.readlines()
+
+                for ind, line in enumerate(data):
+                    match = primary_pattern.search(line)
+
+                    if match:
+                        line = re.sub(primary_pattern,
+                                      match.group().split('](')[0][1:], line)
+
+                    data[ind] = line
+
+                with open(os.path.join(root, file), 'w') as markdown:
+                    markdown.writelines(data)
+
+
+def modify_changelog():
+    """Change first line of the changelog to markdown Heading 1.
+    This modification makes sure that in the pdf build, changelog is a new
+    chapter.
+    """
+    with open('src_copy/src/CHANGES.md', 'r') as file:
+        data = file.readlines()
+
+    data[0] = "# Changelog"
+
+    with open('src_copy/src/CHANGES.md', 'w') as file:
+        file.writelines(data)
+
+
+def correct_table(table, offset=[0.0, 0.0], debug=False):
+
+    """Create the corrected table.
+
+    Compute the number of characters maximal in each table column and reformat each 
+    row in the table to make sure the first and second rows of the table have enough
+    dashes (in proportion) and that fences are correctly aligned
+    for correct rendering in the generated PDF.
+
+    Parameters
+    ----------
+    table : list of list of str
+        Table content extracted from the markdown file.
+    offset : list of int
+        Offset that is used to adjust the correction of number of dashes in the first (offset[0]) and 
+        second (offset[1]) columns by the number specified in percentage. Defaults to [0.0, 0.0].
+    debug : bool
+        If True, print debugging information. Defaults to False.
+
+    Returns
+    -------
+    new_table : list of list of str
+        List of corrected lines of the input table with corrected number of dashes and aligned fences.
+        To be later joined with pipe characters (``|``).
+    """
+    nb_of_rows = len(table)
+    nb_of_cols = len(table[0]) - 2
+
+    nb_of_chars = []
+    for i, row in enumerate(table):
+         # Ignore number of dashes in the count of characters
+        if i != 1:
+            nb_of_chars.append([len(elem) for elem in row])
+
+    # Convert the list to a numpy array and computes the maximum number of chars for each column
+    nb_of_chars_arr = np.array(nb_of_chars)
+    max_chars_in_cols = nb_of_chars_arr.max(axis=0)
+    max_chars = max_chars_in_cols.max()
+
+    # Computes an equal number of dashes per column based on the maximal number of characters over the columns
+    nb_of_dashes = max_chars
+    prop_of_dashes = 1.0 / nb_of_cols
+
+    # Adjust number of characters in first and second column based  offset parameter
+    first_column_width = int(offset[0] * nb_of_dashes) + nb_of_dashes
+    second_column_width = int(offset[1] * nb_of_dashes) + nb_of_dashes
+
+    if debug:
+        print('    - Number of chars in table cells: {}'.format(max_chars_in_cols))
+        print('    - Number of dashes (per column): {}'.format(nb_of_dashes))
+        print('    - Proportion of dashes (per column): {}'.format(prop_of_dashes))
+        print('    - Final number of chars in first column: {}'.format(first_column_width))
+        print('    - Final number of chars in second column: {}'.format(second_column_width))
+
+    # Format the lines with correct number of dashes or whitespaces and 
+    # correct alignment of fences and populate the new table (A List of str)
+    new_table = []
+    for i, row in enumerate(table):
+
+        if i == 1:
+            str_format = ' {:-{align}{width}} '
+        else:
+            str_format = ' {:{align}{width}} '
+
+        row_content = []
+        for j, elem in enumerate(row):
+            # Set the column width
+            column_width = nb_of_dashes
+            if j == 1:
+                column_width = first_column_width
+            elif j == 2:
+                column_width = second_column_width
+            
+            if j == 0 or j == len(row) - 1:
+                row_content.append(elem)
+            else:
+                # Handles alignment descriptors in pipe tables
+                if '-:' in elem and ':-' in elem :
+                    str_format = ' {:-{align}{width}}: '
+                    row_content.append(str_format.format(':-', align='<', width=(column_width)))
+                elif not '-:' in elem and ':-' in elem :
+                    str_format = ' {:-{align}{width}} '
+                    row_content.append(str_format.format(':-', align='<', width=(column_width)))
+                elif '-:' in elem and not ':-' in elem :
+                    str_format = ' {:-{align}{width}}: '
+                    row_content.append(str_format.format('-', align='<', width=(column_width)))
+                elif i == 1 and not '-:' in elem and not ':-' in elem :
+                    str_format = ' {:-{align}{width}} '
+                    row_content.append(str_format.format('-', align='<', width=(column_width)))
+                else:
+                    row_content.append(str_format.format(elem, align='<', width=(column_width)))
+
+        new_table.append(row_content)
+        
+    return new_table
+
+def _contains_table_start(line, debug=False):
+
+    """Check if line is start of a md table."""
+    is_table = False
+
+    nb_of_pipes = line.count('|')
+    nb_of_dashes = line.count('-')
+
+    if debug:
+        print('Number of dashes / pipes : {} / {}'.format(nb_of_dashes, nb_of_pipes)) 
+    
+    if nb_of_pipes > 2 and nb_of_dashes > 2:
+        is_table = True
+
+    return is_table
+
+
+def correct_tables(root_path, debug=False):
+    """Change tables in markdown files for correct rendering in PDF.
+
+    This modification makes sure that the proportion and number of dashes (---) are 
+    sufficiently enough for correct PDF rendering and fences (|) are correctly aligned.
+
+
+    Parameters
+    ----------
+    root_path : str
+        Path to the root directory containing the markdown files
+    debug : bool
+        If True, print debugging information. Defaults to False.
+    """
+    exclude_files = ['index.md', '01-contributors.md']
+    for root, dirs, files in os.walk(root_path):
+        for file in files:
+            if file.endswith(".md") and file not in exclude_files:
+                print('Check tables in {}'.format(os.path.join(root, file)))
+
+                # Load lines of the markdown file
+                with open(os.path.join(root, file),'r') as f:
+                    content = f.readlines()
+
+                tables = []
+                table_mode = False
+                start_line = 0
+                new_content = []
+                for line_nb, line in enumerate(content):
+                    # Use dashes to detect where a table start and 
+                    # extract the header and the dashes lines
+                    if not table_mode and _contains_table_start(line, debug):
+                        # Initialize a list to store table rows
+                        table = []
+
+                        # Set table_mode to True such that the next lines 
+                        # will be append to the table list
+                        table_mode = True
+
+                        # Keep track of the line number where the table starts
+                        start_line = line_nb-1
+
+                        print('  * Detected table starting line {}'.format(start_line))
+                        # Extract for each row (header and the one containing dashes) 
+                        # the content of each column and strip to remove extra whitespace
+                        header_row = [c.strip() for c in content[line_nb-1].split('|')]
+                        row = [c.strip() for c in line.split('|')]
+
+                        # Add the two lines to the table row list
+                        table.append(header_row)
+                        table.append(row)
+
+                    elif table_mode:
+                        # Extract from the line string the content of each column 
+                        # and strip them to remove extra whitespace
+                        row = [c.strip() for c in line.split('|')]
+
+                        # Detect if this is the end of the table and add the row if not empty.
+                        # The end of the table is reached when:
+                        #  * the row is empty (len(row) <= 1)
+                        #  * or the successive row is empty (len(content[line_nb]) > 1)
+                        is_end_of_table = False
+                        if len(row) > 1:
+                            table.append(row)
+                            if line_nb < len(content) - 1:
+                                if not len(content[line_nb]) > 1:
+                                    is_end_of_table = True
+                                    end_line = line_nb
+                            elif line_nb == len(content) - 1:
+                                    is_end_of_table = True
+                                    end_line = line_nb
+                        else:
+                            is_end_of_table = True
+                            end_line = line_nb - 1
+
+                        # If the end of the table is reached, correct the table and 
+                        # append each corrected row (line) to the content of the new markdown content 
+                        if is_end_of_table:
+                            print('    - End of table detected after line {}'.format(end_line))
+                            
+                            # Set table_mode to False such that the script will look 
+                            # for a new table start at the next markdown line 
+                            table_mode = False
+
+                            # Correct the given table
+                            table = correct_table(table, debug=debug)
+                            print('    - Table corrected')
+                            if debug:
+                                print(table)
+
+                            # Update the corresponding lines in 
+                            # the markdown with the corrected table
+                            count = 0
+                            for i, new_line in enumerate(content):
+                                if i == start_line:
+                                    new_content.pop()
+                                if i >= start_line and i < end_line:
+                                    new_content.append('|'.join(table[count])+' \n')
+                                    count += 1   
+                                elif i == end_line:
+                                    new_content.append('|'.join(table[count])+' \n\n')
+                                    count += 1 
+                            print('    - Appended corrected table lines to the new markdown content')
+                    else:
+                        new_content.append(line)
+
+                    line_nb += 1
+
+                # Overwrite with the new markdown content
+                with open(os.path.join(root, file),'w') as f:
+                    f.writelines(new_content)
+
+
+def edit_titlepage():
+    """Add title and version number of the specification to the titlepage."""
+    title, version_number, build_date = extract_header_string()
+
+    with open('cover.tex', 'r') as file:
+        data = file.readlines()
+
+    data[-1] = ("\\textsc{\large "+version_number+"}" +
+                "\\\\[0.5cm]" +
+                "{\large " +
+                build_date +
+                "}" +
+                "\\\\[2cm]" +
+                "\\vfill" +
+                "\\end{titlepage}")
+
+    with open('cover.tex', 'w') as file:
+        data = file.writelines(data)
+
+
+if __name__ == '__main__':
+
+    duplicated_src_dir_path = 'src_copy/src'
+
+    # Step 1: make a copy of the src directory in the current directory
+    copy_src()
+
+    # Step 2: copy BIDS_logo to images directory of the src_copy directory
+    copy_bids_logo()
+
+    # Step 3: copy images from subdirectories of src_copy directory
+    copy_images(duplicated_src_dir_path)
+    subprocess.call("mv src_copy/src/images/images/* src_copy/src/images/", 
+                    shell=True)
+
+    # Step 4: extract the latest version number, date and title
+    extract_header_string()
+    add_header()
+
+    edit_titlepage()
+
+    # Step 5: modify changelog to be a level 1 heading to facilitate section 
+    # separation
+    modify_changelog()
+
+    # Step 6: remove all internal links
+    remove_internal_links(duplicated_src_dir_path, 'cross')
+    remove_internal_links(duplicated_src_dir_path, 'same')
+
+    # Step 7: correct number of dashes and fences alignment for rendering tables in PDF
+    correct_tables(duplicated_src_dir_path)
diff --git a/src/99-appendices/01-contributors.md b/src/99-appendices/01-contributors.md
index c01c5eea49..a685539214 100644
--- a/src/99-appendices/01-contributors.md
+++ b/src/99-appendices/01-contributors.md
@@ -150,7 +150,7 @@ your name is not listed, please add it.
 -   Nicole C. Swann 📖
 -   François Tadel 📖🔌💡
 -   Roberto Toro 🔧
--   Sébastien Tourbier 🤔👀📢
+-   Sébastien Tourbier 🤔👀📢🐛💻📖
 -   William Triplett 📖
 -   Jessica A. Turner 📖
 -   Bradley Voytek 📖