save-place-skip-check-regexp

save-place-skip-check-regexp is a variable defined in `saveplace.el'.
Its value is

"\\`/\\(?:cdrom\\|floppy\\|mnt\\|\\(?:[^@/:]*@\\)?[^@/:]*[^@/:.]:\\)"

Documentation:
Regexp whose file names shall not be checked for readability.

When forgetting unreadable files, file names matching this regular
expression shall not be checked for readability, but instead be
subject to `save-place-save-skipped'.

Files for which such a check may be inconvenient include those on
removable and network volumes.

You can customize this variable.