Update README.md

Author: onepiecefreak3

README.md

@@ -12,8 +12,23 @@ Various options have to be set to properly use the command line tool.
 | - | - |
 | -h | Shows a help text explaining all the options listed here and examples on how to use use them. |
 | -o | The operation to execute. Has to be followed by either:<br>`d` to decompress a script<br>`e` to extract a script to human readable code<br>`c` to create a scripot from human readable code |
-| -t | The type of .xq file to process. Is only necessary for operation `c`. Has to be followed by either:<br>xq32<br>xseq |
-| -f | The file to execute the operation on. |
+| -t | The type of .xq file to process. Is only necessary for operation `c`. Has to be followed by either:<br>`xq32`<br>`xseq` |
+| -f | The file or directory to execute the operation on. |
+
+### Method name mapping
+
+In the file `methodMapping.json` instruction types, that are not known by the program (see "Instructions" in the script specification), can be mapped to a human readable name.<br>
+Since those unknown instructions are normally game specific logic, they have to be figured out by the user and added to the mapping for themselves.
+
+If an unknown instruction type has no corresponding mapping, its name will be set to `subXXX`, where `XXX` is the instruction type.
+
+### Reference scripts
+
+Scripts can call methods from within themselves and other scripts currently loaded in the engine. Normally, those calls happen via the CRC32/CRC16 of the function name to invoke them.<br>
+To resolve those checksums back into human readable names, reference scripts can be placed in the folder `reference` next to the command line tool.
+
+It is recommended to put every script of a game in the references to have the highest probability of properly resolving all checksums.<br>
+However, there is no guarantee that a checksum will be resolved, so user action has to be taken.
 
 ## Examples