Variable: buffer-auto-save-file-format
buffer-auto-save-file-format is a buffer-local variable defined in
buffer.c.
Documentation
Format in which to write auto-save files.
Should be a list of symbols naming formats that are defined in format-alist.
If it is t, which is the default, auto-save files are written in the
same format as a regular save would use.
Probably introduced at or before Emacs version 22.1.
Source Code
// Defined in /usr/src/emacs/src/buffer.c
DEFVAR_PER_BUFFER ("buffer-auto-save-file-format",
&BVAR (current_buffer, auto_save_file_format), Qnil,
doc: /* Format in which to write auto-save files.
Should be a list of symbols naming formats that are defined in `format-alist'.
If it is t, which is the default, auto-save files are written in the
same format as a regular save would use. */);