Building unixodbc-2.2.14p2 on debian/squeeze which you just fetched through apt-get source unixodbc.
apt-get source unixodbc
Current Asterisk (telephony software) version 1.6.2.x (and probably 1.4 and 1.8), has an odd quirk with the qualify option.
It is not uncommon to have a database with records that just accumulate and accumulate over time. Think of log files, telephony billing records, traffic data and so forth.
Sometimes you need to access your source code repository-server from a new server which hasn't been whitelisted yet. You check out the source over port 22, but you can't, because traffic from new-server to 22 is rejected.
When reproducing an issue with IP phones speaking SIP, I ran into the question of how to switch source port on my linux NAT router.