How do you identify a Dalit?

" There is no way to distinguish Dalits from Rest of the Indians. We all look Indians . Anybody including "rest of the Indians" , Whites , Blacks , Hispanic can claim to be a Dalit if they have a Valid caste certificate. IF you are not Indian then let me tell you caste system in Hinduism is a very complicated thing , you won't be able to realize it by reading some pages , You have to come to India and Feel it in Real to know what is exactly going on . "
Dalits are Unhygienic? : first of all You can not just tell whether the person is Dalit or not , the only way to identiy him is to ask for caste certificate or he tells you . Now how can you say something like that ? That means all Unhygienic people are Dalits. Somebody misguided you .
Discrimination : It happens mostly in "Uneducated India" it doesn't matter whether it is Urban or Village it doesn't matter and people who discriminate are always Prejudiced.
I am a Dalit . and the question you asked , rest of the Indians ask themselves too and they even don't know the answer .
If I wish I can disappear and no longer be a Dalit . I am Indian

You cannot distinguish a Dalit from any other person. The colour of their skin, the way they dress or speak, everything is like any other person. It is all in the mind!

I don't think so it happens in towns now, it used to happen in villages and now also it happens in some villages , it's not about the matter of hygiene , royal people made people dalit to maintain their supremacy and things became worse u know...

i think they get some certificate issued by gov proclaiming they are backward caste /tribe

A Dalit can be identified if you look at the caste certificate issued by the government. Caste details are also asked while filling up details for college admissions and government jobs.

I don't think a Dalit looks that much different than a person from an upper caste or mid level caste. Caste was based on occupation and intellect rather than physical traits.

So a Dalit is by birth, according to the parents caste, and imposed by the government by issuing the caste certificate as such.

A follow up question is: Are Dalits against being Dalits, or just against the discrimination ?