What is the definition of lime?
Vinegar is very useful for bringing a 'sour' or 'tart' flavour to dishes. There are no real precautions, other than to use a little at a time because if you put too much in at once, it will pretty much ruin the recipe. Lime has a similar function, but a more 'citrusy' flavour; it goes great with Mexican-style dishes. No real precautions other than, try not to squirt it in your eyes - it's not a pleasant sensation. :)