MakiMaki, > if ($numeric isin 312 318) { halt }will only check the first condition, that being the 312 to be compared. 318 will be overlooked. If you don't believe me, ask someone experienced in MSL, and he or she'll tell you what you have shown is incorrect.

What you're looking for is this:

if ($numeric isin 312) || ($numeric isin 318) { halt }

While isin will work but still not considered proper as Dean mentioned.

Your latest example is deemed correct, and it'll work as shown.