Re: Rejecting messages without a subject line #suggestion
I think divining intent from semantics is a perilous business, in particular when there are multiple plausible intents.
Some people may intend to start a new thread by changing the subject line.
Some people may intend to just clean up automated reply/forward annotations.
Some people may intend to acknowledge that the subject of the conversation has mutated while preserving the chain to the earlier subject (the thread has forked).
Some people may intend to just add or remove a hashtag.
None of those are more right or more wrong than the others, just different use cases. Asserting that only one of them is what all writers have in mind strikes me as not very universal.
PG&E Delenda Est