+`feature`
+~~~~~~~~~
+Require that fast-import supports the specified feature, or abort if
+it does not.
+
+....
+ 'feature' SP <feature> LF
+....
+
+The <feature> part of the command may be any string matching
+^[a-zA-Z][a-zA-Z-]*$ and should be understood by fast-import.
+
+Feature work identical as their option counterparts with the
+exception of the import-marks feature, see below.
+
+The following features are currently supported:
+
+* date-format
+* import-marks
+* export-marks
+* relative-marks
+* no-relative-marks
+* force
+
+The import-marks behaves differently from when it is specified as
+commandline option in that only one "feature import-marks" is allowed
+per stream. Also, any --import-marks= specified on the commandline
+will override those from the stream (if any).
+
+`option`
+~~~~~~~~
+Processes the specified option so that git fast-import behaves in a
+way that suits the frontend's needs.
+Note that options specified by the frontend are overridden by any
+options the user may specify to git fast-import itself.
+
+....
+ 'option' SP <option> LF
+....
+
+The `<option>` part of the command may contain any of the options
+listed in the OPTIONS section that do not change import semantics,
+without the leading '--' and is treated in the same way.
+
+Option commands must be the first commands on the input (not counting
+feature commands), to give an option command after any non-option
+command is an error.
+
+The following commandline options change import semantics and may therefore
+not be passed as option:
+
+* date-format
+* import-marks
+* export-marks
+* force
+