GDDI — Consider changing Total Length from 3 to 4 octets or add "trimmed" wording

Comment from Matteo Vescovi:
8.1.2.4 Total Length
"This integer PIM attribute maps to a CORBA unsigned long whose most significant 8-bits are unused, resulting in a 24-bit (3 octet) field as shown in the above figure."

I'm curious why the standard CDR rules were not followed, and it was decided to encode an unsigned long as 3 octets instead of 4? To save one octet? To limit max message size?

Also, figure 17 has "CORBA unsigned long" next to the Total Length field, which might be misleading. Perhaps it should say "CORBA unsigned long (trimmed)" or similar, to alert the reader to the fact that the usual CORBA unsigned long CDR marshalling does not apply to this field.