Can one enforce a patent while it is only &quot;pending approval&quot;?
<p>When does a patent begin taking effect, exactly?</p>
<p>And if it takes effect BEFORE being officially approved (which seems strange to me), can the patent's author enforce the patent (for example, through demands to cease or negotiate, and filing of complaints with a professional body like the ACM) without communicating the content of the patent? This would seem to open the door to all kind of abuses.</p>

<p>Patents become enforceable when granted, not before.</p>
<p>However there is something called provisional rights (absolutely nothing to do with provisional applications). In the US, under <a href="https://www.uspto.gov/web/offices/pac/mpep/mpep-9015-appx-l.html#d0e303482" rel="noreferrer">35 USC 154(d)</a>, if a claim in a published application is “substantially identical” to a claim that eventually issues, a patent owner can get damages of at least a reasonable royalty on units produced between the publication and notice and the issue date. Enforcement on this must await the granting of the patent.</p>
<p>The infringer must have actual notice of the published application. It is rarely invoked see <a href="https://www.kramerlevin.com/images/content/4/3/v2/43719/preserving-provisional-rights-pre-issuance-patent-damages.pdf" rel="noreferrer">this article</a>.</p>

<p>An accusation against you to ACM should have details stating what you are accused of. If not, then ACM should reject the accusations. If yes, ACM should tell you what you are accused of. If someone accuses you of something that they know you haven't done (like being in violation of a patent that doesn't exist), that might be libel, and you'd need a lawyer.</p>
<p>If I <em>had</em> a patent application and it was still pending, I believe it is legally fine for you to violate the patent <em>now</em>, but it would be risky, because once the patent is accepted, you would be in trouble. Now I might <em>believe</em> that violating the patent is illegal while it is still pending, and I might accuse you of doing something that I reasonably believe is illegal, and then making the accusation would be wrong but legal. If I haven't even applied for the patent, that's different.</p>
<p>Now if I accuse you legally, and then refuse to provide any evidence, that doesn't make the accusation illegal, but it makes it very weak. For example ACM should reject such an accusation, even if it was true (because they cannot know whether it is true or not). If you sued me for libel, and I still refused to show the evidence, the judge would be allowed to conclude that the evidence doesn't exist and judge against me in the libel case.</p>
<p>PS. The question you see is only vaguely related to the one I replied to.</p>

patents