\fBzstd\fR offers \fIdictionary\fR compression, useful for very small files and messages\. It\'s possible to train \fBzstd\fR with some samples, the result of which is saved into a file called a \fBdictionary\fR\. Then during compression and decompression, reference the same dictionary\. It will improve compression ratio of small files\. Typical gains range from 10% (at 64KB) to x5 better (at <1KB)\.