diff --git a/X16 Reference - 04 - BASIC.md b/X16 Reference - 04 - BASIC.md
index 0d54b08..89f810e 100644
--- a/X16 Reference - 04 - BASIC.md	
+++ b/X16 Reference - 04 - BASIC.md	
@@ -84,6 +84,7 @@ for GitHub's Markdown flavor. Do not remove!
 | `LOG` | function | Returns the natural logarithm of a number | C64 |
 | [`MENU`](#menu) | command | Invokes the Commander X16 utility menu | X16 |
 | `MID$` | function | Returns a substring from the middle of a string | C64 |
+| [`MOD`](#mod) | function | Returns the truncated remainder of a division | X16 |
 | [`MON`](#mon) | command | Enters the machine language monitor | X16 |
 | [`MOUSE`](#mouse) | command | Hides or shows mouse pointer | X16 |
 | [`MOVSPR`](#movspr) | command | Set the X/Y position of a sprite | X16 |
@@ -950,6 +951,30 @@ The values are 1-based. If no column is given, only the line is changed.
 MENU
 ```
 
+### MOD
+
+**TYPE: Function**  
+**FORMAT: MOD(<dividend>, <divisor>)**
+
+**Action:** Returns the truncated remainder of <dividend> divided by <divisor>
+
+The `MOD` function supports 16bit signed numbers (-32768 to 32767)
+
+**EXAMPLE of MOD Function:**
+```BASIC
+PRINT MOD(-17, 5)        :REM RESULT WILL HAVE THE SAME SIGN AS DIVIDEND
+-2
+
+PRINT MOD(17, 5)
+ 2
+
+PRINT MOD(42, 0)         :REM DIVISOR IS 0, RETURN ERROR
+?DIVISION BY ZERO ERROR
+
+PRINT MOD(65000, 101)    :REM DIVIDEND IS TOO LARGE FOR A SIGNED 16BIT VALUE
+?ILLEGAL QUANTITY ERROR
+```
+
 ### MON
 
 **TYPE: Command**