Does the MCS need to explicitly call out differences to LSB? Two areas come to mind: (1) features not required (2) features (particularly libraries) which are uplevel from LSB, and thus may require more than is specified in LSB.
Not sure this is complete, but there is now a section 5.2, which contains the language about the dynamic linker (see bug 5751). Note that section 5.1 ends with a reference to a nonexistent table of differing library versions, which is clearly not correct - need to either add such a table or remove the reference.