I was reading an older thread in HSNL that mentioned its OK if your opponent knows what you have as long as you play correctly knowing that they know what you have. Thread is
here.
I usually try to undefine my hand as much as possible while still extracting value: making my weak hands look stronger and my strong hands look weaker. When I have a great hand and feel my opponent has a strong second best hand, or when I think he is pot committed, I will "define" my hand with a big bet that I expect to be called the large majority of the time.
Defining your hand seems like a more valuable concept in limit HE since raising with one pair is so much more common to lower odds for chasers, even though they often come along anyway. In NL pot odds are so easily manipulated that there's less need to do this.