THE WINHELP |TTLBTREE INTERNAL FILE
===================================

The |TTLBTREE file serves as a lookup table, to obtain the title of a
topic from its offset within the |TOPIC file.  See b_tree.doc for a
general description of b-trees.  This file is used primarily by the
Search dialog box of the WinHelp program, although it is present in
help files which do not use keyword searching.  (The "History" window
seems to get its titles directly from the help text.)

The index pages use as their key values four-byte offsets within the |TOPIC
file.  These offsets are in the form of "Character" offsets; see the section
on offsets in topic.doc.

The leaf pages contain variable-length records, which consist of a four-byte
"Character" offset followed by a zero-terminated ASCII string containing the
title of the corresponding topic.  The records are sorted in numerical order
by their offset values.  Every topic has a record in the TTLBTREE file.
