thin-film is forbidding as a tag
Interference in thin films is a standard 1st-year physics topic. It would be nice to be able to label applets I create about it with this standard name for the topic. However, both thin-film and thinfilm are forbidden as tags. What is going on here? What am I supposed to call this topic? It belongs to the larger class of interference phenomena, but it's a distinct sub-category. This is the name every one of the tens of intro textbooks I have gives this topic.