When researching about the _doClick related concepts, I found a hack that might possibly be a serializaied representation of the memory segment where a formula command will be stored in a server.
This sounds funny and frightening to me - "Yin and Yang" concept, if I am not wrong.
Well as usual try the following ridiculous stuff and tell me that I am not crazy.
1. Create/open a form in Lotus Notes
2. Create a button and put some formula code inside it as illustrated in the following screen shot.
4. Now preview the form in browser and you will be able to see some thing like this
Man this stuff is crazy.