PUBLIC MARKS from ycc2106 with tag folksonomies

* Misspelt tags (e.g., libary, libray) * Badly encoded tags, such as unlikely compound word groupings (e.g.,TimBernersLee) * Tags that do not follow convention in issues such as case and number; singular versus plural form (e.g., apple, apples) * Personal tags that are without meaning to the wider community (e.g., mydog) * Single-use tags that appear only once in the database. (e.g., billybobsdog)