I have a silly question: how does one call a commission that is not meant to be paid (at all or not with real money)?

I have been calling them "requests", in the sense that they are a request from someone, not a placed order like a paid commission would be. However, the word request is normally used as being what people wanting a commission make.

Specifically, I'm looking for a word or expression that I would be able to use on GaiaOnline, for example, where a fake online currency, Gaia Gold, is used. Saying "I only do paid commission" on there often results in people reassuring me that they intent to pay well... in Gaia Gold. Sadly, that will not pay my bills. Moreover, most dictionaries define a commission by being something one pays for in one form or another, most usually in cash.

So do you guys know of any way to clearly express a difference between those 'real-money paid commissions' and 'not paid or not paid with real money commissions'?

Art requests paid with another piece of art are clearly differentiated as art-trades but I can't find anything self-explanatory for this distinction.

In short other news, oh hey, it's December already. I will probably make some posts about Otakuthon's Artist Alley and Yaoithon soon.