Hi Eli,

Sorry for my misunderstanding for your preview comments.

> but wouldn't it be better to use symbols instead of strings?

The new option `dired-compress-files-default-suffix` can be “.tar.gz” or “.tar.xz”… and it should work with variable ` dired-compress-file-suffixes` while this variable maybe extended by user. So the type:string is simple for implementation.

And yes, the document need update, changes are available in the attachment.

Please help to review the new patch. Thanks.