compression.md

@@ -63,11 +63,12 @@ The distance base is the current output position
 (`distance = ((code[0] << 4) & 0x0F00) | code[1]`),
 therefore the maximum distance is 4095 octets.
 
-On decoding length octets are copied to the output position,
-starting from initial output position minus distance.
-Please note that source and destination can/will overlap
-(copy single octets, neither use memcpy, nor
+On decoding length count octets are copied to the output,
+starting from current output position minus distance.
+Please note that this is not a memory copy, but a sequence
+(copy octet by octect - no 'optimizations', neither use memcpy, nor
 [memmove](https://en.cppreference.com/w/c/string/byte/memmove#Notes)).
+See the example stream where a match generates 18 from 2 octects. 
 
 Please note that the distance value could be 0. This would result in
 undefined behavior during decompression (if the implementation does