Adjustable loop (crochet)?

[Fenhir Noble]

I'm reading crochet patterns and "Adjustable loop" keeps popping up... what is that and how do you make one?  

[Brunette_Star]

I just googled it and found a site with photos and a tutorial - is this what you mean? (I'm a crocheter and haven't found an adjustable loop in any of my patterns.)

http://www.crochetme.com/Dec_Jan_0405/reads_round.html

Another way I can think of "adjustable loop" being used is to make a slip knot to start a foundation chain.