Some confirmation from Symbian ver. 7 docs

Finally looked at the UIQ/ver 7 sdk documents. I corrupted the install initially ,trying to get out of installing an earlier Java runtime, and then tried deleting the installed files and install information. Took me a few days, during which I unzipped some of the install packages to get at the Rcomp binary. End result is that the installed2.xml file had to have the bad install entries removed.

Regarding the various RSC formats and offset 0x2, from the sdk....

v5.1-v6.1 legacy Unicode resource format

This two-byte integer (in little-endian byte order) stores 1 + the size of the resource index in bytes. The addition of 1 was to distinguish this resource file format from an older, now obsolete, resource-file format.

The only change was to distinguish between the Unicode and non-Unicode files. "older, now obsolete":) Designing a resource file that uses the same 4 uid header as most of their other system files would have been better, allowing a simpler interface. Good thing that's what Symbian did with the version 7 rsc format.

v7.0 dictionary-compressed resource format

The format is supported by the resource reading APIs, but Development Kits do not currently contain a resource compiler that produces this format.

This version is designed to compress all Unicode strings without the occasional expansion trouble of Unicode standard compression.

v7.0 compressed Unicode resource format

Note that resources in either of these two formats may contain uncompressed Unicode: this is because compressing Unicode using the Standard Compression Scheme for Unicode can, in certain conditions, yield larger output than input, hence such Unicode text-strings will not be compressed as it would not be beneficial.

Comments in the source for Rcomp refers to a "dictionary-compressing program" other than Rcomp itself. This reduces the varieties of RSC files in the wild to two, the series 60 uncompressed Unicode file and the UIQ 4 Uid header file.