In the course of developing specifications for one patent application, one of the subordinate details envisioned and described among alternate embodiments seems to have potential to be split off into a separate application. It is shown in the drawings. If it is suggested as an embodiment detail of the first application but not explicitly included in claims, can it then be written up as a separate application? The first application has not yet been filed, except as provisional.
Q. "Can it then be written up as a separate application?"
A. Yes. Each of the two regular applications should claim priority to the provisional application which you have already filed. To do that, the regular applications must both be filed within one year of the provisional filing date.
The inventors of the two regular applications are not necessarily the same. But, for each regular application at least one inventor must have been an inventor named in the provisional application. Naming the proper inventors in each regular application depends on who invented the inventions claimed in that application.
Example: A, B and C are inventors named in the provisional application. A and B are inventors in one regular application and C is the inventor in the other regular application because A and B invented what is claimed in the first application while C invented what is claimed in the second application.