What does "for your information" mean?

Used to introduce a rebuttal to the interlocutor's previous statement, especially when the statement angered or offended the speaker.

For your information

prep_phrase, slang

prep_phrase, slang ·Moderate ·College level

Prep_phrase

1
Used to introduce a rebuttal to the interlocutor's previous statement, especially when the statement angered or offended the speaker. colloquial
"For your information, my son was a straight A student in college, so he's not just some schmo!"
2
Used as a satiric preface to highlight information that an interlocutor should already know or should be able to surmise. colloquial
"For your information, you're reading English in Wiktionary."
3
Used other than figuratively or idiomatically: see for, your, information.
"I kept the dates and times in the logbook for your information."

"For your information, my son was a straight A student in college, so he's not just some schmo!"