Is there a Phone Number + Extension format that is recognized by both the iPhone and Blackberry devices?

For example, if I set up a meeting request in an online Calendar, I can provide a dial-in phone number for the conference call service plus the extension for my particular “room”, such as 1 (800) 555–1212 extension 97531.

Blackberry devices can auto-dial that entire thing if I provide that information as:
1–800-555–1212 X97531

iPhone devices can auto-dial that entire thing if I provide that information as:
1–800-555–1212p97531

I hate having to put redundant information in the meeting request twice, but have not yet come up with a format that works with both devices.

Have you?