+* robots
+
+ Causes the robots meta tag to be written:
+
+ \[[!meta robots="index, nofollow"]]
+
+ Valid values for the attribute are: "index", "noindex", "follow", and
+ "nofollow". Multiple comma-separated values are allowed, but obviously only
+ some combinations make sense. If there is no robots meta tag, "index,
+ follow" is used as the default.
+
+ The plugin escapes the value, but otherwise does not care about its
+ contents. In particular, it does not check the values against the set of
+ valid values but serves whatever you pass it.
+
+* guid
+
+ Specifies a globally unique ID for a page. This guid should be a URI
+ (in particular, it can be `urn:uuid:` followed by a UUID, as per
+ [[!rfc 4122]]), and it will be used to identify the page's entry in RSS
+ and Atom feeds. If not given, the default is to use the page's URL as its
+ guid.
+
+ This is mostly useful when a page has moved, to keep the guids for
+ pages unchanged and
+ [[avoid_flooding_aggregators|tips/howto_avoid_flooding_aggregators]].
+