Reorg multiple sections consolidate what you can/can't do to the schema into one section and move to the top of the Tracker Schema section.. Also outline how you *can* change the type of a property. In the "Classes and Properties - creating a new information store section", add new Method subsection after Properties subsection. Place all 4 method sections in there moving them from below. Move IssueClass section before FileClass section because IssueClass incorporates links to FileClass not the other way around. Fix indexes.

try:
    from html import escape as html_escape_  # python 3

    def html_escape(str, quote=False):
        # html_escape under python 3 sets quote to true by default
        # make it python 2 compatible
        return html_escape_(str, quote=quote)
except ImportError:
    # python 2 fallback
    from cgi import escape as html_escape  # noqa: F401