I've read and heared the phrase "Please be adviced" many times. Is it a passive or other type of grammar?

Thank you for your time!
I assume you meant "Please be advised".

Yes, technically it's passive. To advise someone is to give them advice, therefore to be advised is to recieve advice. "Please be advised" means "Please receive advice". Usually, the referenced advice will be found in the same sentence, for example "Please be advised that your lease expires next week", which - technically - means "I advise you that your lease expires next week" ... with one important difference.

When expressed in the active voice ("I advise you that..."), the subject of the verb ("I", in this case) must be stated explicitly, whereas...

...when expressed in the passive voice ("Be advised that..."), the advice-giver may be omitted.

Businesses therefore tend to prefer the passive version, as it considerably more vague about who is responsible for the advice!

Of course, "Please" doesn't do much, grammatically. Normally "please" is used to construct a request, or to make a request more polite. In this instance, however, it's just part of business language, and is utterly insincere.

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Rommie, your explaination is really clear. Thanks!

Rommie, fantastic explanation...cheers!