diff --git a/docs/database-format.md b/docs/database-format.md
new file mode 100644
index 0000000..c1b4955
--- /dev/null
+++ b/docs/database-format.md
@@ -0,0 +1,27 @@
+SIMDB version 2
+===============
+
+Database header format - fixed length, 48 bytes
+
+    Bits  | Contents
+    ------+------------------------------------------
+     0-15 : "IMDB vXX, CAPS: "
+    16-23 : capabilities, terminated with ';'
+    24-48 : padding with null's
+
+Database record format - also fixed length, 48 bytes:
+
+     # | off | len | description
+    ---+-----+-----+-------------------------------------------------------
+     1 |   0 |   1 | record is used
+     2 |   1 |   1 | overall level of color: R--
+     3 |   2 |   1 | overall level of color: -G-
+     4 |   3 |   1 | overall level of color: --B
+     5 |   4 |   2 | image width
+     6 |   6 |   2 | image height
+     - |   8 |   8 | reserved for future use
+     7 |  16 |  32 | bitmap, each 2 bytes is row of monochrome image 16x16
+
+    field |  12345 6 +       7
+    map   |  XRGBWWHH________MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
+    sect  |  [     0-15     ][    16-31     ][    32-48     ]
diff --git a/src/database.h b/src/database.h
index 58f4b8f..c620e8b 100644
--- a/src/database.h
+++ b/src/database.h
@@ -24,33 +24,6 @@
 
 typedef struct _simdb_t simdb_t; /* opaque database type */
 
-/**
-  Database header format - fixed length, 48 bytes
-
- 0-15 : "IMDB vXX, CAPS: "
-16-23 : capabilities, terminated with ';'
-24-48 : padding with null's
-*/
-
-/**
-  Database record format - fixed length, 48 bytes
-
- # | off | len | description
----+-----+-----+-------------------------------------------------------
- 1 |   0 |   1 | record is used
- 2 |   1 |   1 | overall level of color: R--
- 3 |   2 |   1 | overall level of color: -G-
- 4 |   3 |   1 | overall level of color: --B
- 5 |   4 |   2 | image width
- 6 |   6 |   2 | image height
- - |   8 |   8 | reserved for future use
- 7 |  16 |  32 | bitmap, each 2 bytes is row of monochrome image 16x16
-
-field |  12345 6 +       7
-map   |  XRGBWWHH________MMMMMMMMMMMMMMMMMMMMMMMMMMMMMMMM
-sect  |  [     0-15     ][    16-31     ][    32-48     ]
-*/
-
 #define REC_OFF_RU  0 /* record is used */
 #define REC_OFF_CR  1 /* color level: red */
 #define REC_OFF_CG  2 /* color level: green */