They rather complicated gerunds on that thread. Gerunds are simply 'ing' forms of verbs that function as nouns, plain and simple. A gerund is about as easy to spot as a post oak. One person on that thread mentioned 'candle lighting ceremony'--and in that instance 'lighting' would no longer qualify as a gerund because the function in that nouns phrase was adjectivial. Take any verb, turn it into the present participle form, let it function adjectivially, and you simply end up with a present participle functioning as an adjective; that same 'ing' present participle form of the verb functioning purely as a noun in a sentence is what we call gerunds.

"We went to the candle lighting." Lighting there is a gerund.

"We went to the candle lighting ceremony." Lighting there is a present participle functioning as an adjective.