diff --git a/scsh/odbc/odbc.scm b/scsh/odbc/odbc.scm
index a39eea8..660c578 100644
--- a/scsh/odbc/odbc.scm
+++ b/scsh/odbc/odbc.scm
@@ -92,18 +92,19 @@
 (define sql-datasources-fetch-first 2)
 
 ;;; C type identifier
-(define sql-type-c-char 1)
-(define sql-type-c-long 4)
-(define sql-type-c-short 5)
-(define sql-type-c-float 7)
-(define sql-type-c-double 8)
-(define sql-type-c-numeric 2)
-(define sql-type-c-default 99)
-(define sql-type-c-date 9)
-(define sql-type-c-time 10)
-(define sql-type-c-timestamp 11)
-(define sql-type-c-binary -2)
-(define sql-type-c-bit -7)
+(define sql-type-c-char 1)         ; SQL_C_CHAR
+(define sql-type-c-long 4)         ; SQL_C_LONG
+(define sql-type-c-short 5)        ; SQL_C_SHORT
+(define sql-type-c-float 7)        ; SQL_C_FLOAT
+(define sql-type-c-double 8)       ; SQL_C_DOUBLE
+(define sql-type-c-numeric 2)      ; SQL_C_NUMERIC
+(define sql-type-c-default 99)     ; SQL_C_DEFAULT  (not mentioned in Appendix D?!?!?)
+(define sql-type-c-date 9)         ; SQL_C_DATE
+(define sql-type-c-time 10)        ; SQL_C_TIME
+(define sql-type-c-timestamp 11)   ; SQL_C_TIMESTAMP
+(define sql-type-c-binary -2)      ; SQL_C_BINARY
+(define sql-type-c-bit -7)         ; SQL_C_BIT
+; missing: all the SQL_C_INTERVAL* stuff
 
 ;;; ODBC type identifier
 (define sql-type-unknown 0)     ; SQL_UNKNOWN_TYPE