Which types of patent applications are not published?

Provisional applications are not published because they are considered temporary and do not undergo the same examination process as nonprovisional applications. They serve primarily as a means for inventors to secure an early filing date while giving them up to 12 months to file a corresponding nonprovisional application that will be examined and published.

The United States Patent and Trademark Office (USPTO) does not publish provisional applications, allowing inventors to maintain confidentiality during the provisional period. This confidentiality can be advantageous for inventors who wish to further develop their inventions or seek funding without revealing details publicly.

On the other hand, nonprovisional applications, once filed, are eventually published after 18 months from the earliest priority date unless the applicant requests non-publication under specific circumstances. International applications, particularly those filed under the Patent Cooperation Treaty (PCT), also undergo publication at the time of international publication. Thus, provisional applications stand out as they do not have a process leading to publication.