scmJS docs

STRx

The string table of StarCraft: Remastered: the same as STR with 32-bit numbers, so the table has no 64 KB limit. Only Remastered reads it, and it is always UTF-8. A map with STRx does not need STR.

Name STRx (53 54 52 78)
Size Whatever the text needs.
Read by The game.
Required In place of STR on a Remastered map that uses it.
More than one copy Only the last copy counts.
In scmJS Read, and written again when you change what it holds.

Layout:

Offset Type Holds
0 u32 How many strings there are
4 u32 × that many Where each string starts, counted from the start of the section
after the offsets text The strings, each ending in a 0 byte