Zabbix UI was recently changed to spell out condition operators - for example, "=" was changed to "equals". While the change itself seems weird (parsing the dropdowns is now slower, especially with ">=" now being a mouthful of "is greater than or equals"), but that is unlikely to get reverted

A confusing disconnect now exists between the UI / the main docs (that got updated) and the API docs.

For example, https://www.zabbix.com/documentation/4.0/manual/api/reference/action/object#action_filter_condition is now completely disconnected from everything else, and reader has to figure out how one set of operators translates to the other.