Question

I can’t seem to find a definitive answer on this — what does the p in JSONP stand for?. The candidates I’ve found so far are padding and prints. Anyone know where the JSONP name came from?

Answer 1

Padding.

from http://en.wikipedia.org/wiki/JSONP

JSONP or “JSON with padding” is a complement to the base JSON data
format, a pattern of usage allowing a page to request data from a
server in a different domain. JSONP is a solution to this problem,
forming an alternative to a more recent method called Cross-Origin
Resource Sharing.
Padding

While the padding (prefix) is typically the name of a callback
function that is defined within the execution context of the browser,
it may also be a variable assignment, an if statement, or any other
Javascript statement. The response to a JSONP request (namely, a
request following the JSONP usage pattern) is not JSON and is not
parsed as JSON; the returned payload can be any arbitrary JavaScript
expression, and it does not need to include any JSON at all. But
conventionally, it is a Javascript fragment that invokes a function
call on some JSON-formatted data.

Said differently, the typical use of JSONP provides cross-domain
access to an existing JSON API, by wrapping a JSON payload in a
function call.

Hope that helped. Google wins!