Type: Bitmap
    Extension: SHG
      Version: 
  Compression: None, RLE
  Color Depth:
   Maintainer: Microsoft Corporation
Specification: ftp://ftp.microsoft.com/developr/drg/Multimedia/SHED.ZIP

SHG is a file format used by Microsoft in the WinHelp on-line help facility
found in Windows 3.1. This format is used to save a Microsoft Bitmap (BMP) or
Windows Metafile (WMF) graphic and store the coordinates of specific areas of
the bitmap known as "hotspots".  When the bitmap is displayed and the user
selects a hotspot, WinHelp jumps to another part of the help documentation
via a hyper-text link macro stored in the SHG file.

Another file format used with SHG files is the Multiple-Resolution Bitmap
(MRB) format. MRB files contain one or more SHG images, each rendered at a
different resolution. Several SHG files are typically created using the
SHED.EXE utility and then fed into the MRB compiler to create a single MRB
file. When WinHelp reads the MRB file it chooses which bitmap most closely
matches the resolution of the display.

SHG is currently officially undocumented by Microsoft, but a rather
questionable specification may be found at:

  ftp://ftp.microsoft.com/developr/drg/Multimedia/SHED.ZIP

Information on SHG and MRB may be found in the following journal article:

  .mrb and .shg File Formats, Windows/DOS Developer's Journal, Pete Davis,
    February 1994 (Vol 5, No 4), pp. 37-46.

Questions about these formats may also be directed to Section 16
(WinHelp/Tools) of forum WINSDK on CompuServe.