Windows Help and Help Compiler Capacity Limits

The information in this article applies to:

• Microsoft Windows Software Development Kit (SDK) for Windows version 3.1

SUMMARY

The following lists the limits of the Windows Help application, version 3.1. These limits are subject to change in future versions.

Paragraph size(1): approximately 32,000 bytes Topic title string length: 127 characters Topics per RTF source file: approximately 32,700 Topics per help file: 42,000,000 By-reference bitmaps per help file : 32,767 Help file size: approximately 2,157,000,000 bytes (2 gigabytes) Topic footnote character limit: 1023 characters

Keywords per help file: limited only by file size Keyword length: 255 bytes Topics per keyword(2): < 800 Browse sequence length: limited only by the number of topics

Bookmarks per help file: limited only by file size Annotations per topic: 1 Annotations per help file: 32,767

History list length: 40 topics Text that can be copied to clipboard: limited only by machine memory

Macro length: 512 characters

Main windows per topic: 1 Secondary windows per topic: 5

(1) The maximum paragraph size includes graphics pasted into the RTF source. Therefore, each pasted graphic is limited to 32,000 bytes. To work around this limitation, import large bitmaps by reference.

(2) Performance degrades for files with more than several hundred topics. The Search dialog box displays a maximum of 400 topics.