This is survey of newswire/editorial policies adopted by various other IMCs. The quotes below are deliberately highlighted to illustrate how other collectives have chosen to deal with (or exclude outright) content which they believe conflicts with their missions. The opinions represented here belong to whichever IMC is cited, not STLIMC.

IndyBay.org (Bay Area)
Intentionally makes its definition of "newswire abuse" vague, since "editorial collective participants each have different conceptions of what this means, so each proposal to hide/edit posts or comments will be taken on a case-by-case basis." No obvious link to hidden/removed content.
http://www.indybay.org/newsitems/2002/08/04/1395001.php [1]

OKIMC.org (Oklahoma)
Explicit list of content which the ed collective may remove, e.g. "discriminatory or abusive posts, libelous or slanderous posts - choose your language carefully." No obvious link for hidden content.
http://okimc.org/guidelines [2]
Also, unregistered users must submit via a special form, which presumably goes to a queue reviewed by the eds. Also added: "We cannot guarantee publication for material sent via this form."
http://okimc.org/submit [3]

arkansas.indymedia.org
Explicit list of content which the ed collective may remove, e.g "racist, sexist, homophobic, or otherwise promoting hatred and intolerance" and "Postings that organize specific illegal acts."
http://arkansas.indymedia.org/mod/info/display/policy/index.php [4]

chicago.indymedia.org
Will hide "newswire posts that are racist, sexist, homophobic, or that clearly fly in the face of our mission to serve as a space for the exchange of news, dialogue and opinion that advances economic and social justice."
http://chicago.indymedia.org/mod/info/display/about/index.php#editorial [5]

ucimc.org (Urbana-Champaign)
Their ed policy specifically cites "Illegal Speech," e.g. threats against the US president, and "Direct Threat." Hiding posts is performed by a Steering Committee.
http://www.ucimc.org/info/editpolicy [6]
Also, they have set up a hidden page:
http://ucimc.org/hidden [7]

houston.indymedia.org
Ed policy specifically listed what sort of content may be hidden, e.g. "advocate criminal activity with a specific time, place and manner" and "hatred toward or repression of any individual or group of people."
http://houston.indymedia.org/process/about.php [8]

colorado.indymdia.org
"In order to deal with problems with spamming you must first create an account to publish your content. You do not have to give any personal information to set up an account. Thanks for your understanding, Colorado Indymedia."
http://colorado.indymedia.org/node/add [9]