What is meant by “check” in a radiogram header?

In the National Traffic System (NTS) radiogram format, the 'check' is a specific administrative field in the message preamble. Its primary purpose is to ensure that no part of the message text has been lost during transmission. The check is simply a count of the number of words (or word equivalents, like punctuation marks written out as words) in the text portion of the radiogram. When a station receives the message, the operator counts the words in the text and compares it to the 'check' number to verify accuracy. It does not refer to a checkmark box for relay status, nor does it refer to the call sign or relay history of the stations handling the message.