Just to clarify, regarding Contents.m working for 'normal' folders my understanding was that if the folder was 'accessible' but not added 'itself 'to the path  (i.e. similar to how @ and + folders work), then help would find its contents.

However, I just checked with matlab, and this is not true for matlab either, it only works if you explicitly add the normal folder to the path.

The rest applies for @ and + folders though.
One extra point to note, if a class has a constructor of the same name, matlab shows the documentation for the constructor and seems to ignore the contents file.

Therefore the main missing functionality here is for + folders.

Also, there is no documentation anywhere in the octave project for this functionality, it may be useful to add this in the docs somewhere. (I think this is also the case for +folders in fact).

It used to be that Octave supported Contents.m file functionality, similar to matlab (https://uk.mathworks.com/help/matlab/matlab_prog/create-a-help-summary-contents-m.html) such that if one called the help function for a folder name, this would display the contents of the Contents.m file contained within as the official documentation for the folder.

This was also the case for @class folders, as well as for +namespace folders (without the @ or + characters, as far as I'm aware?)

This functionality was definitely present in the past, I've used it myself, and there's evidence in the bug tracker too, e.g. see #40342 . I also note there are many official octave packages that make use of such a Contents.m file (e.g. matgeom).

Was this functionality removed at some point? Or is this a regression bug?


(For some background context on what triggered this bug report: https://stackoverflow.com/questions/65019819/how-do-i-make-octave-suggest-the-methods-of-my-class-when-i-hit-tab-and-show-the )