You cannot specify a level 88 condition for non-standard value types; that is, value types such as decimal, character, and value-type. However, you can specify level 88 conditions on standard value types, such as binary-long and float-short.
01 n1 decimal. *> not allowed 88 cond-1 value null. 01 c1 character. *> not allowed 00 cond-2 value null. 01 d1 type System.DateTime.*> not allowed 88 cond-3 value null. 01 p1 type MyValueType. *> not allowed 88 cond-4 value null. 01 l1 float-long. *> allowed 88 cond-5 value null. 01 s1 binary-short. *> allowed 88 cond-6 value null. end program. valuetype-id MyValueType. 01 inst binary-long. end valuetype.