So your U.S. patent application got rejected, but when you read the Office Action you found a section titled "Allowable Subject Matter." Congratulations! That means you are probably going to get a patent! But why are these claims merely "allowable" and not actually allowed? Typically, it is because they are dependent claims that depend on a rejected claim, so a few changes will need to be made before you get your Notice of Allowance.
A non-provisional patent application always includes one or more claims. These are the numbered items at the end of every patent or non-provisional patent application. The claims set forth the legal bounds of your invention -- they are the description of what you claim to own. You will typically have one or more independent claims and one or more dependent claims. Each of the dependent claims depends on one of the independent claims.
For example, consider the following set of claims:
1. A device comprising element A and element B.
2. The device of Claim 1, further comprising element C.
3. The device of Claim 2, further comprising element D.
Claim 1 is independent and Claim 2 is dependent, since it depends on Claim 1. Claim 3 is also dependent, as it depends on both Claim 2 and, through Claim 2, Claim 1. In this instance, Claim 1 is considered the base claim while Claim 2 is considered the intervening claim.
If the Examiner finds prior art showing a device with elements A and B, the Examiner will reject Claim 1. If, however, the Examiner does not find prior art showing a device with elements A, B, and C or rendering such a claim obvious, the Examiner will merely object to Claims 2 and 3 with the following language:
Claims 2 and 3 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
You then have three options. The first is to argue about Claim 1 and try to convince the Examiner that he or she is wrong and that Claim 1 actually is allowable. The second option is to cancel Claim 1 and amend Claims 2 and 3 as suggested by the Examiner. The amendments would read as follows:
2. The device of Claim 1, further A device comprising element A, element B, and element C.
3. The device of Claim 2, further A device comprising element A, element B, element C, and element D.
Claim 2 is amended to include the limitations of the base claim, Claim 1, while Claim 3 is amended to include the limitations of the base claim, Claim 1, and the intervening claim, Claim 2. This leaves you with two allowable independent claims. But what if you had other claims depending on Claim 1? How do you make sure they are allowable, too? One way is to change every claim, making them depend on either Claim 2 or Claim 3. But what if you already had three independent claims, the maximum allowable without paying an additional fee? These problems lead to your third option: add the allowable subject matter to Claim 1. This makes not only Claim 1 allowable but every claim depending on Claim 1 allowable, as well, without having to change them or changing the number of independent claims in your application. Your amendments would read as follows:
1. A device comprising element A and element B and further comprising element C.
3. The device of Claim []1, further comprising element D.
As you can see, you can cancel Claim 2 because you moved its limitation to Claim 1. Your only other change is to make Claim 3 depend directly on Claim 1, since Claim 2 no longer exists. Now Claim 1 is allowable, as are all claims depending on Claim 1.
Both option 2 and options 3 should result in a Notice of Allowance, assuming all other issues raised in the Office Action are likewise addressed. I say "should" rather than "will" because there is always the chance the Examiner may change his or her mind or the Examiner's supervisor may disagree with the decision to allow the claims, but this is fairly rare. Typically, amending the claims as described above results in a Notice of Allowance. If you then pay your Issue Fee, you will receive your patent.