Third party programs
P-REC (POV-Record) is an third party plugin created by Orange, the plugin is verified by Valve. P-REC is an useful plugin, it's used for easy demo recording in Team Fortress 2, it automatically records matches you play (unless specified otherwise). There are several plugin modes that you can use in in-game console:
(prec_mode 0) - Don't record at all.
(prec_mode 1) - Record only when name of the next demo is set by user.
(prec_mode 2) - Record games with tournament mode enabled. (Default)
(prec_mode 3) - Record all time.
The plugin automatically detects if you do a long killing spree and saves demo file name, time and tick of your respawn before spree into a text document which is called "KillStreaks.txt". You can also manually mark time / tick by binding a key with prec_mark, for example "bind j prec_mark", if you press J in-game while recording it'll mark the tick and time you clicked.