diff --git a/calldata/README.md b/calldata/README.md
index 409cd42..ea34db4 100644
--- a/calldata/README.md
+++ b/calldata/README.md
@@ -7,13 +7,17 @@
 <br>
 
 * calldata is the encoded parameter(s) sent on functions by smart contracts to the evm (for example, through `abi.econde()`,`abi.econcdeWithSelector() for a particular interfaced function, or `abi.encodePacked()` for efficient dynamic variables). 
+
 * `selector()` generates the 4-bytes representing the method in the interface: this is how the evm knows which function is being interacted.
 
 * each piece of calldata is 32 bytes long (64 chars), where 20 hex == 32-bytes
+
 * types:
    - static variables: the encoded representation of `uint`, `address`, `bool`, `bytes`, `tuples`
    - dynamics variables: non-fixed-size types: `bytes`, `string`, dynamic and fixed arrays `<T>[]`
 
+* opcodes are 1 byte in length, leading to 256 different possible opcodes. the EVM only uses 140 opcodes.
+
 <br>
 
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