diff --git a/csst_ms_sls2d.md b/csst_ms_sls2d.md
index c6ee24d19f24732c247e8cee5fdaf965310861f2..24e18ae157c909c856ff1272c9f5e1bedc07e1c7 100644
--- a/csst_ms_sls2d.md
+++ b/csst_ms_sls2d.md
@@ -29,7 +29,7 @@
 
 | keyword    | value                | comment                      | fallback_value | type | module               |
 | ---------- | :------------------- | ---------------------------- | -------------- | ---- | -------------------- |
-| CTYPE1     | 'RV---TPV'           |                              | 'RV---TPV'     | str  | csst_ms_sls_position |
+| CTYPE1     | 'RA---TPV'           |                              | 'RA---TPV'     | str  | csst_ms_sls_position |
 | CTYPE2     | 'DEC--TPV'           |                              | 'DEC--TPV'     | str  | csst_ms_sls_position |
 | CUNIT1     | 'deg  '              |                              | 'deg'          | str  | csst_ms_sls_position |
 | CUNIT2     | 'deg  '              |                              | 'deg'          | str  | csst_ms_sls_position |