Encoding rule for default clearance depth for Wreck

[FrankHippmann]

The DCEG 13.5 states:

The ECDIS "system" attribute default clearance depth must be populated with a value, which must not be an empty (null) value, if the attribute height has not been populated and the attribute category of wreck is populated or the attribute value of sounding is populated with an empty (null) value.

This implies that default clearance depth must be populated for the following Wreck, for example:

category of wreck: 1 : non-dangerous wreck

My thinking based on my understanding is as follows.

Can we express the condition more simply as:

if the attribute value of sounding is populated with an empty (null) value.

The rationale is that if value of sounding is empty/unknown (null), then height and category of wreck must not be present. Similarly for Obstruction and Underwater/awash rock, if value of sounding is empty/unknown (null), then height must not be present.

To put it another way, default clearance depth is only required as a substitute for value of sounding, i.e., when value of sounding is unknown and encoded as null.

[TDYCARHugh]

Not sure about the height etc but I do agree that "default clearance depth is only required as a substitute for value of sounding"

Jeff pointed out something in another discussion that made me wonder if Default Clearance depth was really needed because the clearance value could be assigned to Value of Sounding along with qualityOfVerticalMeasurement set to Least Depth Unknown, Safe Clearance at Value Shown.