@subheading Keywords applicable for @command{tar --extract}
@table @asis
+@kwindex existing-file
+@cindex @samp{%s: skipping existing file}, warning message
+@item existing-file
+@samp{%s: skipping existing file}
@kwindex timestamp
@cindex @samp{implausibly old time stamp %s}, warning message
@cindex @samp{time stamp %s is %s s in the future}, warning message
This keyword defines the value of the @samp{mtime} field that
is written into the ustar header blocks for the extended headers.
By default, the @samp{mtime} field is set to the modification time
-of the archive member described by that extended headers.
+of the archive member described by that extended header (or to the
+value of the @option{--mtime} option, if supplied).
@item globexthdr.name=@var{string}
This keyword allows user control over the name that is written into
--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0
@end smallexample
+@noindent
+If you extract files from such an archive and recreate the archive
+from them, you will also need to eliminate changes due to ctime, as
+shown in examples below:
+
+@smallexample
+--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0,ctime:=0
+@end smallexample
+
+@noindent
+or
+
+@smallexample
+--pax-option=exthdr.name=%d/PaxHeaders/%f,atime:=0,delete=ctime
+@end smallexample
+
@node Checksumming
@subsection Checksumming Problems