Slackware tagfiles

What are Slackware tagfiles? What purpose do they serve these days? Essentially tagfiles provide a list of all packages in a Slackware package series (a, ap, d, e, etc) and the installation priority (add, skip, recommended or optional) of each package. Tagfiles are used internally by the Slackware installer to manage the various prompting modes. User-made tagfiles can also be used to customise the…