The category is the code, or letter, that is placed next to the document cited in the examiner search report. Each of these codes gives you an indication of how close the citation is to the target patent. In other words, certain categories can tell you whether the cited patent is prejudicing novelty, either alone or taken in conjunction with one or more other patents.

The rejection code is the USPTO 102 or 103 rejections. A 102 rejection is a novelty rejection, and a 103 rejection is an obvious rejection. Note also that AcclaimIP breaks down the 103 rejections further to show you where in the obviousness argument the document was used. For example, the 103.4 tells you that document in question was the fourth in the obviousness argument.

Generally, the rejections in the Forward Cites are considered the most important, as it is an examiner using the patent in focus against another application. If this is interesting to you, the Rejections tab holds a great deal more information, so switching over to that tab will tell you more.

The phase code indicates the prosecution phase in which the citation was referenced.

For example, APP means that it was cited by the applicant. There are about a dozen different phase codes. Hovering over the phase code in AcclaimIP will give you a short definition, or right mouse click and you can then click to see the entire list of codes and the short definitions.

This is important to know where during the process the citation occurred, as different phases can have different importance. Examiner citations are generally considered more important than the applicant during the application process.

The CFM (or Citing/Cited Family Member) Count column is fairly straight forward. 

In the Reverse Cites tab - Family Citations sub-tab, the CFM Count is the Citing Family Member count. In other words, how many family members of the patent in focus has cited a particular document. Generally speaking, this count will be fairly low, as most patents don't have huge families. But there are some very important analytics that we can derive from this, including the Uncited Art Score in the next section. 

For example, in the screenshot below, line 4 has a count of 2. This means that out of the family of the patent in focus (the '217 patent), two different application families from that particular simple family have cited that US document (the '920 patent). 

In the expander row, you can see which of the '217 patent's simple family members have cited the '920 patent. We already know that, because of the DC column, the '217 patent (since it is the patent in focus) has directly cited it. By using the expander row, we see the CN family also cited it.

In the Forward Cites tab - Family Citations sub-tab, the CFM Count is the Cited Family Member count. In other words, how many other application families have cited a simple family member of the patent in focus. Generally speaking, this number will be 1, as it's rare that an application will cite more than one member of a prior application's family.

For example, in the screenshot below, the '288 patent cited the '545 patent. That '545 patent is the family member of the patent in focus (the '217 patent). 

It is rare that a patent will cite more than one family member, as the entire family covers the same novel invention, but it is possible.