You can use biological flags to tag the taxa in your classification with special characteristics. This could be biogeographic information, morphological or ecological properties, conservation status, or anything that's important for your group.
To set up a biological flag, go to 'Manage Classification > Add Classification'. Give your new vocabulary a name, e.g., Conservation Status, enter a 'Description' if you like and 'Help text' with instructions for your collaborators, if needed. Now select the 'Biological flag' box and click on the Save button at the bottom of the page. Once your new biological flag is set up, you can start adding vocabulary terms by going to 'Administration > Content Management: Tags, Flags, Ranks, Classifications'. Find your biological flag and click on add terms. Add your terms to the list one by one.
When you're done, go to 'Manage Classification > Tree Editor' and select a taxon. Now open the 'Name Data Panel' and click on 'Biological Flags' where you will find a pulldown menu with the terms from your biological flag.
For easy bulk editing of biological flags, you can also use the 'Grid Editor' (under 'Manage Classification'). If you start typing, it will autocomplete to match a term from your vocabulary.