The term "known if" seems to be a combination of words that might not be commonly used together in English. It could be interpreted as a phrase used to indicate the acknowledgment of a condition or a situation depending on whether a certain criterion is met. In a better-defined context, phrases like "whether known" or "it is known if" could be more appropriate.
The phrase "known if" consists of the word "known," which is the past participle of "know," derived from the Old English "cnÄwan," meaning "to know, to recognize." The word "if" comes from the Old English "gif," used to introduce conditional clauses.