A link that does not look like a URL—i.e., does not start with a known scheme or a file name—refers to the current document. You can follow it with C-c C-o when point is on the link, or with a mouse click (see Handling Links).
Org provides several refinements to internal navigation within a document. Most notably, a construct like ‘[[#my-custom-id]]’ specifically targets the entry with the ‘CUSTOM_ID’ property set to ‘my-custom-id’. Also, an internal link looking like ‘[[*Some section]]’ points to a headline with the name ‘Some section’25.
When the link does not belong to any of the cases above, Org looks for a dedicated target: the same string in double angular brackets, like ‘<<My Target>>’.
If no dedicated target exists, the link tries to match the exact name of an element within the buffer. Naming is done, unsurprisingly, with the ‘NAME’ keyword, which has to be put in the line before the element it refers to, as in the following example
#+NAME: My Target | a | table | |----+------------| | of | four cells |
Ultimately, if none of the above succeeds, Org searches for a headline
that is exactly the link text but may also include a TODO keyword and
tags, or initiates a plain text search, according to the value of
org-link-search-must-match-exact-headline.
Note that you must make sure custom IDs, dedicated targets, and names are unique throughout the document. Org provides a linter to assist you in the process, if needed. See Org Syntax.
During export, internal links are used to mark objects and assign them a number. Marked objects are then referenced by links pointing to them. In particular, links without a description appear as the number assigned to the marked object26. In the following excerpt from an Org buffer
1. one item 2. <<target>>another item Here we refer to item [[target]].
The last sentence will appear as ‘Here we refer to item 2’ when exported.
In non-Org files, the search looks for the words in the link text. In the above example the search would be for ‘target’.
Following a link pushes a mark onto Org’s own mark ring. You can return to the previous position with C-c &. Using this command several times in direct succession goes back to positions recorded earlier.
To insert a link targeting a headline, in-buffer completion can be used. Just type a star followed by a few optional letters into the buffer and press M-TAB. All headlines in the current buffer are offered as completions.
When targeting a ‘NAME’ keyword, the ‘CAPTION’ keyword is mandatory in order to get proper numbering (see Captions).