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### 3.4 Tags Tables for Info Files

You can speed up the access to nodes of a large Info file by giving it a tags table. Unlike the tags table for a program, the tags table for an Info file lives inside the file itself and is used automatically whenever Info reads in the file.

To make a tags table, go to a node in the file using Emacs Info mode and type `M-x Info-tagify`. Then you must use `C-x C-s` to save the file. Info files produced by the `makeinfo` command that is part of the Texinfo package always have tags tables to begin with.

Once the Info file has a tags table, you must make certain it is up to date. If you edit an Info file directly (as opposed to editing its Texinfo source), and, as a result of deletion of text, any node moves back more than a thousand characters in the file from the position recorded in the tags table, Info will no longer be able to find that node. To update the tags table, use the `Info-tagify` command again.

An Info file tags table appears at the end of the file and looks like this:

         ^_^L
         Tag Table:
         File: info, Node: Cross-refs^?21419
         File: info,  Node: Tags^?22145
         ^_
         End Tag Table

Note that it contains one line per node, and this line contains the beginning of the node's header (ending just after the node name), a ‘`DEL`’ character, and the character position in the file of the beginning of the node.