Final answer:
The exception to using a TREC-promulgated contract form can be found in transactions involving commercial properties.
Step-by-step explanation:
The exception to using a TREC-promulgated contract form can be found in transactions involving commercial properties. Typically, commercial real estate deals require more complex and specific contracts than residential transactions, so parties may utilize customized agreements.
While transactions with out-of-state parties and transactions with minor modifications may also deviate from a TREC-promulgated contract form, the question specifically asks for an exception, and these situations are not exceptions but rather variations of the standard form.
Similarly, transactions under duress do not qualify as exceptions to using a TREC-promulgated contract form because the form is still required even in stressful or pressured situations.