Posted before but restarting:
https://en.wikipedia.org/wiki/Dumpster
Something any "reference encyclopedia" should have. But it's a sad little near-stub: only about 5k bytes and created in 2007.
On the other hand, there is this.
https://en.wikipedia.org/wiki/Dumpster_diving
One of Wikipedia's oldest articles, dating from 2001. Cuerrently more than 43k bytes long. Why do Wikipedians think dumpster diving is more important that the dumpster one dives into? Is there any kind of sane explanation for this?