When searching for hosts by facts with the ~/LIKE operator, entering a simple keyword without wildcards would have added % to the start and end of the value to match it anywhere (e.g. facts.foo ~ bar). Documented under wildcards at http://theforeman.org/manuals/1.10/index.html#4.1.5Searching.

Since #11150, the wildcards have to be added manually, e.g. facts.foo ~ %bar%, which shouldn't be necessary.