[This is preliminary documentation and subject to change.]
An icon file can hold several different size images of the same icon. These two bits determine which size image of the icon is loaded. If neither bit is set, the first image is loaded. If only the lower bit is set, the first 16x16 image is loaded. If only the higher bit is set, the first 32x32 image is loaded. If both bits are set, the first 48x48 image is loaded.
If the FixedSize bit is set, these bits determine the size of the image displayed.
CheckBox
Icon
PushButton
RadioButtonGroup
None.
0x00200000 = 2097152
0x00400000 = 4194304