I'm using TinyMCE.
Sometimes I type some computer code on a page or in the text of a question (for example, Java code).
To keep the indentation, I switch to the Moodle HTML editor and write my code there, enclosed in a <pre></pre> HTML element.
When I need to type a tab char for indenting, I copy and paste that char from an external text editor.
Alternatively, I can write the code in Notepad++ and then copy and paste it into the Moodle HTML editor.
Well, when I save that page or that question, Moodle does a good job and shows me a perfectly indented Java code.
But I noticed that each tab char was expanded to 8 spaces.
I think it's excessive for me, so I would ask you if I can customize the tab expansion to 4 spaces.