OT: What Does This Symbol Mean

Hi;
Under "Lines for Measures" (translating back from the Spanish) in the pallate there is something that looks like a colon followed by a sidewise (up and down) equals sign followed by another colon. For what is this used? It would appear that it would be dividing two repeats. How is that used? Can someone give an example? Does one repeat the first so many times then repeat the second so many times?
TIA,
Beno