On the Save/Download tab you can choose to give your tagset of variables a name (circled below). You can
Your saved tagset can then be accessed through the Manage Tagsets tab.

The tagset file is simply a text file with a list of the variables you selected. The list will include either (1) Reference Numbers (RNUMs) or (2) Question Names (QNames) with the survey year appended. You can choose either type of list when you save the tagset. There is no functional difference in Investigator between the two options. RNUMs are the traditional unique identifier used in NLS data sets, while QNames sometimes incorporate a brief indication of the variable’s content (such as CV_HGC for “Highest Grade Completed”).
Because the tagset file is a text file, you can open it in any text editor (such as WordPad) and make changes if desired. This is a convenient way to combine two or more different tagsets.