# Validation

* Are there KYC / AML checks?
* Is there a max cap on tokens?
* What if that cap is per-participant?
* Is there a starting and ending time frame?

There are a bunch of different validation requirements that your crowdsale might be a part of:

### CappedCrowdsale

Adds a cap to your crowdsale, invalidating any purchases that would exceed that cap

### IndividuallyCappedCrowdsale

Caps an individual’s contributions.

### WhitelistCrowdsale

Only allow whitelisted participants to purchase tokens. this is useful for putting your KYC / AML whitelist on-chain!

### TimedCrowdsale

Adds an `openingTime` and `closingTime` to your crowdsale