What are signs of water damage?

[sjabosi]

So I got my myTouch 3G 1.2 (yay!). The phone looks mostly clean and everything works fine. However, on the battery there's a tab with red/pink lines criss-cross patterns on it. Does that mean it's been exposed to water?

 

[Andy in NY]

I dont believe so, as most phones I've had thus far have the red criss crosses on them.

 

[copestag]

when it gets wet those criss cross lines will blur and become a reddish square