When editing a map, I can name plans whatever I want, but in the plan editor, when I try to name them, it says only letters, digits, and spaces are allowed. There's nothing stopping me from putting illegal characters in the plan's name from the map editor. The same is true of naming static sprite instances. In my case, I was trying to use colons in the plan names. Specifically, something like "Message: Entry" "Message: Off Limits" etc. It would be useful to be able to use colons in plan names, and perhaps replace them with underscores at compile time.
Speaking of which, underscores are perfectly acceptable as far as the compiler was concerned, but the plan editor wouldn't let me put them in as part of the name.
The other thing I wanted to mention is that I really like how I can alphabetize the plans list, and I wish there were a way to do the same with the sprites list. Manual ordering would also be useful.