The following paragraph is from the 2008 year manual of the PBP.

"These definitions must be in all upper case, exactly as shown. If not, the
compiler may not recognize them. No error message will be produced for
DEFINEs the compiler does not recognize"

After Darrels post, re-reading this paragraph, made me realize that indeed the word define can be either in capital or small. The definitions, and not the DEFINEs, must be in all upper case.

OK. Thanks.

Ioannis