41.23.1 Usual Display Conventions

Here are the conventions for displaying each character code (in the absence of a display table, which can override these conventions; see Display Tables).

The above display conventions apply even when there is a display table, for any character whose entry in the active display table is nil. Thus, when you set up a display table, you need only specify the characters for which you want special display behavior.

The following variables affect how certain characters are displayed on the screen. Since they change the number of columns the characters occupy, they also affect the indentation functions. They also affect how the mode line is displayed; if you want to force redisplay of the mode line using the new values, call the function force-mode-line-update (see Mode Line Format).

User Option: ctl-arrow

This buffer-local variable controls how control characters are displayed. If it is non-nil, they are displayed as a caret followed by the character: ‘^A’. If it is nil, they are displayed as octal escapes: a backslash followed by three octal digits, as in ‘\001’.

User Option: tab-width

The value of this buffer-local variable is the spacing between tab stops used for displaying tab characters in Emacs buffers. The value is in units of columns, and the default is 8. Note that this feature is completely independent of the user-settable tab stops used by the command tab-to-tab-stop. See Adjustable Tab Stops.