For the JSON API, You have "params" as a magically formatted string with LineFeed characters to separate items.

This should be an array of strings for consistency and ease of use.

Introduced in ZBXNEXT-1443

Also, item.create and item.object do not properly document the parameters or the functions. item.get has some notice about what the preprocessing values and functions can be, but only in the select by part.

Please reconsider the design of this API. \LF split strings of magical content doesn't make sense from an API user standpoint.