"Illegal/Improper Usage" Of 499 As Revenues ?

I agree, it appears to be misuse for a revenue purpose - especially as a multiple. If you had only a single, it could also be explained as a possible manuscript RFD cancel, which appear in many complete and incomplete forms. A very nice item, too bad it got soaked off its original document.

On a tangent, I have always found "illegal" to be a strong word for these uses, since you didn't get hauled off to jail for it. Somehow "improper use" (as you suggest) or "used contrary to regulations" fits these better, since the government still got its money, just into a different pocket.

Very nice; too bad it's not on its original document to give us context.

I used to call these "illegal usages" but I've started using the term "improper/illegal usages" to cover all the bases.

They were actually illegal, since any document having a postage stamp used to pay the tax was not considered valid and could not be used in court or for any other official use. As long as they were not needed in those capacities they were usually not seen by anyone in legal authority and went unnoticed.

Well, I used to just call them "illegal usages" but got tired of other more established revenue collectors telling me I was wrong to call them illegal.

I guess the mindset is that since there was no enforcement and the practice was tolerated as the tax was paid regardless of the stamp affixed, it doesn't rise to the level that "illegal" connotates, hence "improper".

Another term I have seen used is "nominally illegal".

It wasn't "tolerated", it was "unknown", at least as far as the government was concerned. Suppose you had a lease, for example. You would sit down with the landlord and write it out, sign it and stamp it. It would then go into the landlord's files. As long as both sides lived up to the lease no one else would ever see it. It was only if it was not lived up to and went to court that the stamp used would be noticed, and if it was not a revenue it would not be valid. There were severe penalties for avoiding paying the tax; however if a postage stamp were used the court would feel that there was no attempt to avoid the tax but they would force the lessee to pay it. The reason people got away with this on checks was that the banks were not responsible for paying the tax, so they didn't care (the person who wrote the check was responsible).

BTW, the tax was NOT paid when a postage stamp was used, that money went to the Post Office Department and not the Internal Revenue.