there was a kind of rainbow inside a cloud caused by the moon tonight

[vichug]

...and i don't know what it's called Is that a moondog ? or a moonbow ? knowing that the diffracted light was only visible in a large and thin foggy cloud, probably high in the atmosphere ?

[geckzilla]

Did it look circular? https://www.atoptics.co.uk/halo/circmoon.htm

If not, try looking around atoptics to see if you can find what you saw.

[vichug]

it was possibly an arc of that circle, because the cloud was under the moon, not right in front of it. Thanks, i'll look