I tried searching the coffeecup universe with the word tab and found no answer to my question.
I'd like to know all the tab key behaviours in your editor.
Under tools > preferences > customisation > modify options there are two tab options - tab columns and tab stops.
What values can one type in there and what exactly do they do? For example, I typed the number 4 in both areas and when I hit the tab key on a new line it goes to column 7?
I've noticed that if I manually indent a line with four spaces, then the behaviour of the tab key for the next line matches those four spaces which is a cool default. Also, if I am at the end of an existing indented line and I hit enter, it will start a new line with the cursor at the indented position of the previous line, which is also cool.
The default behaviour for editing a css file is curious. I start typing a selector and then enter the left brace "{". It automatically generates a right brace and positions the cursor immediately after the left brace - so far so good. Now I believe that it is best coding practice to put the selector and left brace on its own line and every option on its own line, and then the right brace on its own line. So when the cursor is automatically positioned after the left brace I hit enter. The cursor is then positioned in column one of the next line instead of (what I believe to be more convenient), tabbed to the first tab stop. Is there any way I can change this please?
Thanks
David Z

Tab Stop
Is the amount the cursor will move when you hit the tab key.
Tab Columns
Is the hard amount for a tab stop. Set your tab stop to 1 then set columns to what you would need. 10 20 30 40 etc.

I for my part think that putting the two curly braces on the same line is a good practice. Search engines, Yslow etc prefer small files, and a lot of white space is not what they want, it increases the file size.

I set the tab stop to 1 and tab columns to 4 8 12 16. When I hit the tab key it puts in two tabs and one space!?!?!?!

Did you put spaces in between each column number? I just tested this and it works in my html editor.

If you are wanting the tabs to always be the same size all the time, go to
Tools->Preferences->Customizations->Modify Options

and uncheck "Smart Tab."