Two disclaimers: I am only junior staff, and I joined staff very recently in the grand scheme of things.
I may echoing Lucio like everyone else, but I think that the charter should include a section of extremely straightforward, almost vague statements everyone agrees upon that define a general steering direction for the site. Guiding principles as opposed to hard and fast instructions:
Staff will maintain the function and quality of the SCP wiki
Staff will promote the wiki as a space for creative writing
Staff will manage the SCP brand
Staff will not use their staff positions to willfully solicit additional attention to their works
The goal, really, would be to declare a firm common ground as a logical and ethical justification for ideally all wiki policy. This may be overambitious. Nonetheless this is roughly what I imagined when I read Gremlingroup's first paragraph above.
Policies, then, would actually go into detail on what these look like. I hesitate to go into greater detail because they might be unnecessarily narrow in scope — I had originally written out "Staff will maintain the function of quality of the SCP wiki by developing tech policies and deleting subpar work" and "Staff will manage the SCP brand by removing licensing violations across the internet and performing internet outreach" but that feels closed-ended to the point of being constrictive, not constructive. I believe this roughly aligns with Bleep's policy diagram from the previous thread.
Beyond having a dedicated section for this "ethical thesis statement", I think collapsible 1 of Ocuin's post covers everything else that I think should be in the central charter as opposed to the policy tree i.e. extent and limitations of staff power and policy creation and implementation. http://05command.wikidot.com/forum/t-14580540/discussion-charter-overhaul-skeleton-ii:electric-boogaloo#post-5244573
If you'll permit me the indulgence of some unnecessary purple prose, the core ethical and structural charter is the trunk of a tree. Policies, then, are branches, to be grafted or pruned as times change.