@15: Happy Warrior (or is it opine??), I did not ask for proof that "therefor" is an English word. It is one, nobody disputed that, but that is not what this discussion is about. It isn't about whether I personally like or dislike the word either (as a matter of fact, I am perfectly indifferent to it as a word, and since I frequently deal with texts of a legal nature I do occasionally use it). And it isn't about prohibiting its use for others either, whatever gave you that idea? Tagging a word to show it is used in a certain context doesn't mean it cannot
be used in others, it just tells you that it probably should not
because a sentence containing this word in a different context will stand out as highly unusual and interrupt the flow of reading.
What this is about is documenting the actual usage of the word, which, I maintain, is virtually non-existent outside the world of laws, contracts and patents. Thus it is also about giving non-native speakers of English a rough guide as to whether this word could be appropriate in their context, to which the answer, if the context is not something to do with laws, contracts or patents, will almost invariably be "no".
Still waiting for evidence to the contrary from you...
FWIW I think the current LEO entry, as shown in #14, is absolutely fine.