In preparing to perform an unofficial webOS 2.1.0 upgrade on my Sprint Palm Pre, I have read that you need to backup your PRL software so I can restore it to my phone later on. This is an important step because Sprint doesn’t offer webOS 2.1.0 for the Original Pre and you won’t be able to use properly update your PRL on a meta-doctored Sprint Pre if you fail to do this step first.
What is PRL you ask? Good question. I don’t really know either. PRL stands for Preferred Roaming List. Is is a database that gets downloaded to a smartphone that uses CDMA radios just like the ones in Sprint and Verizon Pre/Pre+ phones. The database has a list of network IDs that Sprint has network sharing contracts with to allow your phone to “roam” on other carrier’s network towers. (source)
The good folks at webos-internals.org have a wiki page up on how to backup your PRL data before you go ahead and do the meta-doctor webOS 2.1.0 upgrade.
Just an important note: You must use your own PRL data. It is tied specifically to your phone!