[This is preliminary documentation and is subject to change.]
Appends a slot number, a length field, and a string to this message.
Assembly: Persistate (Module: Persistate) Version: 0.6.1.20 (0.6.1.20)
The string is encoded with the current encoding, by default UTF8. The length of the encoded string is appended first (in addition to the length field), so the string can be read back.