The MAXBRANCH option flags blocks that have too many branches. Branches include all conditional jumps and each WHEN in a SELECT statement that can be turned into a branch table.
>>-MAXBRANCH--(--max--)----------------------------------------><
A statement of the form "if a then ...; else ..." adds 1 to the total number of branches in its containing block, and a statement of the form "if a = 0 | b = 0 then ..." adds 2.