TL;DR
TL;DR (phrase) means Too long; didn't read: used to label a short summary of a long piece, or to say something was too long to bother with. Example: “TL;DR: the policy changes in April.”
How to use TL;DR
Learner’s notesIn plain EnglishA one-line summary of something long.
Informal, written. Often the heading of the summary itself.
Fill the gap
Can you complete this real example?
_____: the policy changes in April.
Etymology
An initialism of "too long; didn't read," from internet forums, where it began as a complaint and became a label for the summary itself.