You may have noticed that your Calendar Report has an insufficient number of Absence Codes.
Yet, as you can see by the image below, the default report offers [All] available Absence Reason Codes.
If your Calendar Report lacks some of the codes visible in the image above, it is because the missing letters are absence codes for which no description has been assigned [and] you have set the software to [not] display such absence codes.
The image above is from my software when [all] absence codes are permitted to be visible. Notice that letters A, G, & Q on the image above do not have descriptions but they are still visible.
The image below is from my software [after] having set the app to [not display] absence codes without descriptions. You will notice that the letters A, G, & Q are no longer visible because prior to running the second report, I set the software to [not] display absence codes without descriptions.
To allow all of your available codes to display, please do the following...
1. Click Settings > Global Settings > Attendance.
2. Uncheck the box where it says Display Only Absence Codes with descriptions. See the image below.
3. Click Save > OK > Close.
4. Close out of the software altogether and reopen it.