This is a general question, not specifically Lazarus (although I am using Lazaurs) - essentially, is there a style guide for menus for Windows, macOS and Linux anywhere?
My search engine is coming up blank (well, not blank, just irrelevant entries) on the Windows front. I've found how to add the application menu for macOS, which is a kindof guide?
Basically, as far as I can tell:
macOS has the application menu with "About", "Settings", separator, OS added stuff (including "Quit") first.
I've been told that Windows should have "File" first (with "Exit" being last entry) and "Help" being last (with "About" as the first entry).
Linux - I haven't a clue...assuming it follows Windows conventions.
Then, there is the question of icons on the menu items. It appears that macOS doesn't tend to have them, but Windows does.