The copy, cut and paste directives are supplied by the cutpaste plugin.

With these directives you can store and recall pieces of text in a page:

• [[!cut id=name text="text"]] memorizes the text allowing to recall it using the given ID. The text being cut is not included in the output.
• [[!copy id=name text="text"]] memorizes the text allowing to recall it using the given ID. The text being cut is included in the output.
• [[!paste id=name]] is replaced by the previously memorized text.

The text being cut, copied and pasted can freely include wiki markup, including more calls to cut, copy and paste.

You do not need to memorize the text before using it: a cut directive can follow the paste directive that uses its text. In fact, this is quite useful to postpone big blocks of text like long annotations and have a more natural flow. For example:

[[!toggleable  id="cut" text="[[!paste id=cutlongdesc]]"]]
[[!toggleable  id="copy" text="[[!paste id=copylongdesc]]"]]
[[!toggleable  id="paste" text="[[!paste id=pastelongdesc]]"]]

[...some time later...]

[[!cut  id=cutlongdesc text="""
   blah blah blah
"""]]
[[!cut  id=copylongdesc text="""
   blah blah blah
"""]]
[[!cut  id=pastelongdesc text="""
   blah blah blah
"""]]

This can potentially be used to create loops, but ikiwiki is clever and breaks them.

Since you can paste without using double quotes, copy and paste can be used to nest directives that require multiline parameters inside each other:

[[!toggleable  id=foo text="""
  [[!toggleable id=bar text="[[!paste id=baz]]"]]
"""]]

[[!cut  id=baz text="""
multiline parameter!
"""]]