I thought it was permissible to point to binaries just as long as you don't include binaries in the tarball that's uploaded to the AUR.
There is no strict rule for this - it's rather common sense. Binaries built by the upstream are OK (but if sources are available, then of course it's better to use them, but there's no obligation). Binaries from other sources... it depends. If you download some non-executable data like fonts, then it's justifiable too as long as checksums are provided. Executable from odd-looking sources on the internet, or self-compiled executables are not. 115backup-gtk2 and 115backup-gtk3 are OK - they download the sources directly from the upstream. Upstream doesn't provide sources. Skype works the same way. -- Kind regards, Damian Nowak StratusHost www.AtlasHost.eu