Many users use some main processes with libreoffice-features/functions/commands very often. So they remember howto.
But some other processes & libreoffice-features/functions/commands are used very seldom, maybe once a year or even less, and you forget the process/function, howto do/use it.
e.g. it is sometimes time-consuming to understand some Excel-functions (in the help-section) and how to use them.
It would be a nice feature, if there were places for a user to write down his own howto-notes about the process/features/functions/commands.
These notes should stick to functional entities, maybe toolbars or tools/commands, or UI-Screens ...
So a user will find his own instructions right at the place where he needs this information.
Why does this need a special UI or add some user-defined offline documentation? Just write down your notes in Writer and save at some handy position.
Btw, the program's name is Calc ;-)
Forwarding this to documentation. Don't think a UI change is needed.
Most desktop systems have applications for "sticky notes" where how-to information can be written quite easily.
And LibreOffice has the extended tips to help user with more tips on each of its dialogs widgets, although the extended tips are set in the source code and not user-defined or user editable
Resolving WF then regarding the basic idea of special how-to tips. If you think the extended tooltips need more explanation on a specific area please file another ticket.