Merge branch 'ew/for-each-ref-doc'

* ew/for-each-ref-doc:
  for-each-ref: document `creatordate` and `creator` fields

Author: gitster

Documentation/git-for-each-ref.txt

@@ -142,6 +142,11 @@ In addition to the above, for commit and tag objects, the header
 field names (`tree`, `parent`, `object`, `type`, and `tag`) can
 be used to specify the value in the header field.
 
+For commit and tag objects, the special `creatordate` and `creator`
+fields will correspond to the appropriate date or name-email-date tuple
+from the `committer` or `tagger` fields depending on the object type.
+These are intended for working on a mix of annotated and lightweight tags.
+
 Fields that have name-email-date tuple as its value (`author`,
 `committer`, and `tagger`) can be suffixed with `name`, `email`,
 and `date` to extract the named component.
@@ -153,8 +158,8 @@ line is 'contents:body', where body is all of the lines after the first
 blank line.  The optional GPG signature is `contents:signature`.  The
 first `N` lines of the message is obtained using `contents:lines=N`.
 
-For sorting purposes, fields with numeric values sort in numeric
-order (`objectsize`, `authordate`, `committerdate`, `taggerdate`).
+For sorting purposes, fields with numeric values sort in numeric order
+(`objectsize`, `authordate`, `committerdate`, `creatordate`, `taggerdate`).
 All other fields are used to sort in their byte-value order.
 
 There is also an option to sort by versions, this can be done by using