This is a slightly modified version of my email to the maemo-developers list, in case a Debian person can clear this up for me:
When creating maemo packages, we will tend to take the debian or Ubuntu package and modify it for maemo. However, for C++ libraries, and maybe C libraries, the latest Debian or Ubuntu soname might not be appropriate.
In this context, the soname is the package suffix, such as 0c2a seen in the http://packages.debian.org/unstable/libs/libsigc++-2.0-0c2a>libsigc++ package.
I believe that these suffixes are changed whenever either
- A new version of g++, with a new C++ ABI, is used.
- A new version of libstdc++, with a new ABI, is used.
- A new version of glibc, with a new ABI, is used.
I don’t know what the 0, c, 2, or a parts of the suffix mean, or if suffix is just changed arbitrarily. I can’t find an overview of these in the debian documentation, so I don’t know what might be an appropriate soname for maemo’s own mix of ABI.