The ToS FAQ (http://archiveofourown.org/tos_faq) has several links to Archive FAQ sections done with the old-style section numbers. These will give Error 500 in the current world order, so they need to be updated to the modern section title type links.
In "What do you mean by "collections"?" the text "Learn more about collections" links to "http://archiveofourown.org/faq/18". It should be "http://archiveofourown.org/faq/collections-and-challenges".
In "How can I start a collection?" the text "Please consult our Tutorials" links to
"http://archiveofourown.org/faq/25". There is not yet a posted tutorial for Collections. If that is still the case when this issue is coded, please change it to:
"Please consult the Archive FAQ." linked to "http://archiveofourown.org/faq/collections-and-challenges#createcollection"
If there is a posted tutorial for Collections when this issue is coded please keep the original text and link to it.