Rule 11 Federal Rules Civil Procedure

Federal Rule of Civil Procedure Eleven (11) is the main rule in federal proceedings governing the  motives and actions of lawyers as to the content of what they say. Here are the all the rules, but below is Rule 11. Every state (as far as I know) has a rule comparable to this rule, and you should find and know your state’s rule.
Rule 11. Signing Pleadings, Motions, and Other Papers; Represen-
tations to the Court; Sanctions
(a) SIGNATURE.  Every pleading, written motion, and other paper
must be signed by at least one attorney of record in the attorney’s
name—or by a party personally if the party is unrepresented. The
paper must state the signer’s address, e-mail address, and tele-
phone number. Unless a rule or statute specifically states other-
wise, a pleading need not be verified or accompanied by an affida-
vit. The court must strike an unsigned paper unless the omission
is promptly corrected after being called to the attorney’s or par-
ty’s attention.
(b) REPRESENTATIONS TO THE COURT.  By presenting to the court
a pleading, written motion, or other paper—whether by signing,
filing, submitting, or later advocating it—an attorney or unrep-
resented party certifies that to the best of the person’s knowledge,
information, and belief, formed after an inquiry reasonable under
the circumstances:
(1) it is not being presented for any improper purpose, such
as to harass, cause unnecessary delay, or needlessly increase
the cost of litigation;
(2) the claims, defenses, and other legal contentions are war-
ranted by existing law or by a nonfrivolous argument for ex-
tending, modifying, or reversing existing law or for establish-
ing new law;
(3) the factual contentions have evidentiary support or, if
specifically so identified, will likely have evidentiary support
after a reasonable opportunity for further investigation or dis-
covery; and
(4) the denials of factual contentions are warranted on the
evidence or, if specifically so identified, are reasonably based
on belief or a lack of information.