diff --git a/lib/sqlite3/constants.rb b/lib/sqlite3/constants.rb
index 34d0a792..1414a571 100644
--- a/lib/sqlite3/constants.rb
+++ b/lib/sqlite3/constants.rb
@@ -1,14 +1,41 @@
 module SQLite3
   module Constants
+    #
+    # CAPI3REF: Text Encodings
+    #
+    # These constant define integer codes that represent the various
+    # text encodings supported by SQLite.
+    #
     module TextRep
+      # IMP: R-37514-35566
       UTF8 = 1
+      # IMP: R-03371-37637
       UTF16LE = 2
+      # IMP: R-51971-34154
       UTF16BE = 3
+      # Use native byte order
       UTF16 = 4
+      # Deprecated
       ANY = 5
+      # sqlite3_create_collation only
       DETERMINISTIC = 0x800
     end
 
+    #
+    # CAPI3REF: Fundamental Datatypes
+    #
+    # ^(Every value in SQLite has one of five fundamental datatypes:
+    #
+    # <ul>
+    # <li> 64-bit signed integer
+    # <li> 64-bit IEEE floating point number
+    # <li> string
+    # <li> BLOB
+    # <li> NULL
+    # </ul>)^
+    #
+    # These constants are codes for each of those types.
+    #
     module ColumnType
       INTEGER = 1
       FLOAT = 2
@@ -17,34 +44,77 @@ module ColumnType
       NULL = 5
     end
 
+    #
+    # CAPI3REF: Result Codes
+    #
+    # Many SQLite functions return an integer result code from the set shown
+    # here in order to indicate success or failure.
+    #
+    # New error codes may be added in future versions of SQLite.
+    #
     module ErrorCode
-      OK = 0   # Successful result
-      ERROR = 1   # SQL error or missing database
-      INTERNAL = 2   # An internal logic error in SQLite
-      PERM = 3   # Access permission denied
-      ABORT = 4   # Callback routine requested an abort
-      BUSY = 5   # The database file is locked
-      LOCKED = 6   # A table in the database is locked
-      NOMEM = 7   # A malloc() failed
-      READONLY = 8   # Attempt to write a readonly database
-      INTERRUPT = 9   # Operation terminated by sqlite_interrupt()
-      IOERR = 10   # Some kind of disk I/O error occurred
-      CORRUPT = 11   # The database disk image is malformed
-      NOTFOUND = 12   # (Internal Only) Table or record not found
-      FULL = 13   # Insertion failed because database is full
-      CANTOPEN = 14   # Unable to open the database file
-      PROTOCOL = 15   # Database lock protocol error
-      EMPTY = 16   # (Internal Only) Database table is empty
-      SCHEMA = 17   # The database schema changed
-      TOOBIG = 18   # Too much data for one row of a table
-      CONSTRAINT = 19   # Abort due to constraint violation
-      MISMATCH = 20   # Data type mismatch
-      MISUSE = 21   # Library used incorrectly
-      NOLFS = 22   # Uses OS features not supported on host
-      AUTH = 23   # Authorization denied
-
-      ROW = 100  # sqlite_step() has another row ready
-      DONE = 101  # sqlite_step() has finished executing
+      # Successful result
+      OK = 0
+      # SQL error or missing database
+      ERROR = 1
+      # An internal logic error in SQLite
+      INTERNAL = 2
+      # Access permission denied
+      PERM = 3
+      # Callback routine requested an abort
+      ABORT = 4
+      # The database file is locked
+      BUSY = 5
+      # A table in the database is locked
+      LOCKED = 6
+      # A malloc() failed
+      NOMEM = 7
+      # Attempt to write a readonly database
+      READONLY = 8
+      # Operation terminated by sqlite_interrupt()
+      INTERRUPT = 9
+      # Some kind of disk I/O error occurred
+      IOERR = 10
+      # The database disk image is malformed
+      CORRUPT = 11
+      # (Internal Only) Table or record not found
+      NOTFOUND = 12
+      # Insertion failed because database is full
+      FULL = 13
+      # Unable to open the database file
+      CANTOPEN = 14
+      # Database lock protocol error
+      PROTOCOL = 15
+      # (Internal Only) Database table is empty
+      EMPTY = 16
+      # The database schema changed
+      SCHEMA = 17
+      # Too much data for one row of a table
+      TOOBIG = 18
+      # Abort due to constraint violation
+      CONSTRAINT = 19
+      # Data type mismatch
+      MISMATCH = 20
+      # Library used incorrectly
+      MISUSE = 21
+      # Uses OS features not supported on host
+      NOLFS = 22
+      # Authorization denied
+      AUTH = 23
+      # Not used
+      FORMAT = 24
+      # 2nd parameter to sqlite3_bind out of range
+      RANGE = 25
+      # File opened that is not a database file
+      NOTADB = 26
+      # Notifications from sqlite3_log()
+      NOTICE = 27
+      # Warnings from sqlite3_log()
+      WARNING = 28
+      # sqlite_step() has another row ready
+      ROW = 100
+      # sqlite_step() has finished executing
+      DONE = 101
     end
   end
 end