What is the strangest subject to clause(s) that you have seen?
Please define the question. Do you mean a contingency clause?
Subject to clause is generally in a deed, stating that the grantee takes title "subject to" an existing mortgage.
Would it be different in Canada where OP is from. I have seen subject to--termite inspection, wood mites inspection ( up in No Calif in the forests).
The usual are subject to mortgage appraisal and home inspection.
The funniest thing I've heard of written into an offer specified that the in-ground sprinkling system would convey.