marks specified in <file> before processing any input. For details,
read up on '--import-marks=<file>' in linkgit:git-fast-export[1].
+'signed-tags'::
+ This modifies the 'export' capability, instructing Git to pass
+ '--signed-tags=verbatim' to linkgit:git-fast-export[1]. In the
+ absence of this capability, Git will use '--signed-tags=warn-strip'.