When working with enabling proxy support for a project, we were trying to ensure we documented which versions were needed for features correctly and found that there are conflicts over when features were introduced on these two pages:
http://curl.haxx.se/libcurl/c/curl_easy_setopt.html
http://curl.haxx.se/libcurl/c/symbols-in-versions.html
Under CURLOPT_PROXYTYPE in the setopt doc, it says that CURLPROXY_SOCKS4 was introduced in 7.15.2, whereas the symbols page reports 7.10. Since archived source bundles are difficult to come by, I can't confirm when it became available. Though I happened to have recently compiled software with socks support on a system running 7.15.1, so I know 7.15.2 is inaccurate.
Additionally, the setopt doc reports that CURLOPT_SOCKOPTFUNCTION was introduced in 7.15.6, but the symbols page says 7.16.
There may be other conflicts on the pages, but these are the ones we came across.
Thanks for the report, this problem is now fixed in the git repository.
To try it out, you either checkout/update your git clone: http://curl.haxx.se/source.html
or you try tomorrow's daily snapshot: http://curl.haxx.se/snapshots/