Prosecutors in the Anna Nicole Smith drug conspiracy case want the judge to prohibit defense lawyers from telling the jury there is an "industry-wide practice in the medical community" of using aliases when prescribing to celebs.


According to docs obtained by TMZ, lawyers for Dr. Sandeep Kapoor, Dr. Khristine Eroshevich and Howard K. Stern -- claim it's "standard practice in the medical profession" to use aliases when prescribing celebrities meds to protect their identities.

But according to the prosecution, there is no "celebrity exception" to the law --  it's a crime, prosecutors say, to issue a prescription under a false name or address.

Anna Nicole got numerous prescriptions under phony names, including Michelle Chase.  And, of course, Michael Jackson used nearly 2 dozen aliases.