Final answer:
Brackets [ ] are used to enclose synonyms, alternative wording, or explanatory phrases in a tabular list.
Step-by-step explanation:
In a tabular list, the punctuation marks used to enclose synonyms, alternative wording, or explanatory phrases are brackets [ ]. Brackets are used to indicate a change made to a quotation or to add information to a quotation, providing clarification or explanation. They are also used to clarify the meaning of a word or reference. Therefore, brackets are the correct punctuation marks to enclose synonyms, alternative wording, or explanatory phrases in a tabular list.