https://www.percona.com/doc/percona-server/5.7/myrocks/limitations.html currently says the following:
*_bin (e.g. latin1_bin) or binary collation should be used on CHAR and VARCHAR indexed columns. By default, MyRocks prevents creating indexes with non-binary collations (including latin1). You can optionally use it by settingrocksdb_strict_collation_exceptions to t1 (table names with regex format), but non-binary covering indexes other than latin1 (excluding german1) still require a primary key lookup to return the CHAR or VARCHAR column.
I think it should say "case-sensitive" instead of "binary" and "case-insensitive" instead of "non-binary". For example, see:
All of those documents refer to case (in)sensitivity of collations, rather than the binary / non-binary ones. Which I think is more precise.