What is required for an application to maintain priority from its parent application?

The requirement for an application to maintain priority from its parent application hinges on the condition that it must not introduce new subject matter. This is aligned with the principles of continuity in patent applications, specifically regarding the requirements of 35 U.S.C. § 120, which stipulates that a continuing application must be filed within a specific time frame and need to claim priority in a manner that doesn’t expand the original disclosure.

If an application introduces new subject matter, it essentially alters the scope of what was originally disclosed in the parent application. This can be problematic because the original disclosure is what establishes the foundation for the claimed invention. Therefore, to retain the benefit of the parent application's filing date, the child application must only claim the same subject matter or variations that are not significantly different from what was originally disclosed.

In contrast, containing various independent claims, being filed by the same applicant, or including international patent treaties do not inherently affect the ability to maintain priority. These factors may influence other aspects of patent prosecution but do not directly relate to the core requirement of not introducing new subject matter.