It just occurred to me today that there will be two quite distinct categories of tags. First category: tags like `rank` or `followers`, that will have wide utility and will not specify the algorithm. Followers means verified followers, and lots of people will have lots of ideas of what constitutes "verified," and that's a good thing. Second category: tags that DO specify the algorithm, in ALL of its excruciating detail. These may have detailed human-readable-ish names like `personalizedGrapeRank_influence_attenuation0.6_rigor0.9` or maybe even event ids or naddrs where we can find constants like attenuation and rigor and all of the other details of whichever algo it refers to. New, simple clients may support the first category by default, meaning that they will hardcode the commonly used metrics, like rank to filter spam and followers to stratify content. They won't necessarily need to give users the option to select other tags. Other clients may give users the ability to select lots of metrics for lots of use cases. One pair of metrics to filter and stritify trending list, another pair to filter and stratify responses or reactions, another slew of metrics to display on individual profile pages. Suppose the client lets you select the tag that you use to eliminate spam. This will require not only selection of the tag, like personalizedGrapeRank_influence_attenuation0.6_rigor0.9, but also the cutoff, like 0.1. One tag may range 0 to 100, another tag 0 to 1, another tag something else entirely, and any individual client may or may not provide support for any given tag.