Thanks to Asmus for saying what I had planned to say, except that his was better-worded, more carefully put together, and more authoritative.
Casing for text meant for human readers should follow current local conventions. Casing for text meant for machine processing (file systems, databases, etc.) must remain stable, even when local conventions change. -- Doug Ewell, CC, ALB | Lakewood, CO, US | ewellic.org
