[Cedar]

"index"

???

[txhurl]

It's how you link a thread to yourself. By replying, whether you say BTTT (back to the top), BUMP (to the top), PING (like Internet Protocol Ping or just 'yo, hey' to other like-minded freepers, like in Ping-Pong), or whatever you wish to write, or not, if you are too braindead, busy, drunk, what have you... it's how you can find the thread that interested you later on. 'Indexing' is not a special SQL function/call, for us users, anyway.