AlliedModders - [L4D2]Only allow certain addons? How

I know about whitelist.cfg. But i dont know how to config this file. Please help me.
I wanna some addons allowed in my server. Ex : Mod SI, ...

Quote:

whitelist
{
//
// 4 modifiers are allowed on file specifications:
//
// allow_in_coop - these files can be loaded from addon vpks when in coop mode
// allow_in_addon - these files can be loaded from addon vpks when playing an addon.
// check_crc - these files will always be CRC checked.
// check_every_map - these files will be checked every map
//

//
// Five types of file specifications:
//
// 1. directory\*.* - refers to all files under the directory
// 2. directory\... - refers to all files under the directory and all directories under that (recursively)
// 3. directory\*.*+.ext - refers to all files under the directory with extension .ext
// 4. directory\...+.ext - refers to all files under the directory and all directories under that (recursively) with extension .ext
// 5. directory\filename - refers to a single file

//
// Files to be checked:
//

left4dead2\pak01_dir.vpk check_crc
left4dead2\steam.inf check_crc

left4dead2_dlc1\pak01_dir.vpk check_crc
left4dead2_dlc2\pak01_dir.vpk check_crc
left4dead2_dlc3\pak01_dir.vpk check_crc

update\pak01_dir.vpk check_crc

}