Recovery Mode Explained - 3.71 M33
I haven't written a guide in a while, and I thought that this was one topic that could do with a bit of a clearing up for the PSP newbies, so I decided to write one on this. I did have a huge list with many sub-lists inside it, but it kept displaying wrong, so I got rid of them all and switched to a title-based layout. Nevertheless, I hope it's useful to a few people out there!
Configuration - Skip Sony Logo
If enabled, skips the 'Sony Computer Entertainment' logo that comes up when the PSP is started.
Hide corrupt icons
Hides most of the corrupt icons made by the folders without the % for 1.50 homebrew in PSP/GAME and PSP/GAME150.
Game folder homebrew
Lets you select the kernel used for the PSP/GAME folder. 3.71 is used for demos, official Sony programs and homebrew apps coded for the 3.XX kernel, while 1.50 kernel is for all other homebrew. Bear in mind that a) the 1.50 option doesn't work on PSP Slims and b) the 1.50 kernel and 3.XX kernel are available in the PSP/GAME150 and GAME371 folders respectively, no matter what this option is set at.
Autorun program at /PSP/GAME/BOOT/EBOOT.PBP
If enabled, the EBOOT.PBP file will be run when the PSP starts up.
UMD Mode
Used for running ISOs from the XMB. Here's a breif description of each of the options:
Normal: UMD required -
the most compatible one, but requires a UMD in the drive. M33 Driver: the official M33 driver, the second most compatible one not requiring a UMD. Sony NP9660: a patched version of the official Sony ISO loader. The most compatible one not requiring a UMD. OE isofs legacy: The least compatible one. Should only be used if none of the others work. This was the one used in the OE releases. Fake region
Used to change the region of the PSP.
Free UMD Region
If enabled, in theory, allows any UMDs from any region to be played.
Hard reset on homebrew
If enabled, the PSP will reset when starting homebrew, then load into the homebrew. (I think - please correct me on this one!)
Use VshMenu:
If enabled, when you press SELECT in the XMB, a menu will come up with several options.
XMB USB Device
Allows you to change which device the computer accesses when USB mode is active.
Advanced: Toggle USB (flashX)
Allows you to access the flash0, flash1, flash2 and flash3 of the PSP via USB.
Format flash1 and reset settings
This will wipe your settings completely, letting you start over with them. Very useful if the flash1 (where the settings are stored) becomes corrupt, not letting the PSP boot.
Advanced configuration Plain modules in UMD/ISO
If enabled, code can be run from within an ISO/UMD, allowing things like CheatDevice to work, but also limits compatibilty of certain games.
Excecute BOOT.BIN in UMD/ISO
UMDs (and therefore ISOs too) have two excectuable files: EBOOT.BIN and BOOT.BIN. Normally, EBOOT.BIN is used, but by enabling this, BOOT.BIN is used instead. No real use to non-developers.
Registry hacks: Button assign
Lets you choose which button you use to select stuff in the XMB. Asian PSPs have this as O by default, while all others have it at X.
Activate WMA
Lets you activate WMA without connecting to an access point.
Activate Flash Player
Lets you activate the flash player without connecting to an access point.
Other: Toggle USB
If enabled, USB mode will be active.
CPU Speed
Lets you set the speed of the PSP's CPU in the XMB and in UMDs/ISOs, between 20 and 333 Mhz. Default should be used for most things.
Plugins
Lets you enable/disable installed plugins.
If I got any of this wrong, don't be afraid to tell me!
NOTE TO ADMINS/MODS: I know ISOs are a banned subject, but a guide on the Recovery menu would not be complete without a complete list of its features, so I hope this doesn't cross the line too much! 
Linear Mode
