Proposed BIP for OP_CAT

The email discusses the topic of script size limits in Bitcoin transactions. The sender mentions that without a limit of 520 bytes, it is possible to construct a script using various operations such as CHECKSIGVERIFY and CAT. By repeating the second witness string multiple times on the stack and performing other operations, it is possible to increase the maximum memory required to verify a single script.

The sender provides an example of a larger tapscript, which is a type of Bitcoin script. They share two transaction links as examples: one with 3,938,182 bytes of script (considered non-standard due to its oversized nature) and another with 360,543 bytes of script (considered standard).

Overall, the email highlights the potential for larger script sizes and how they can impact memory requirements for script verification in Bitcoin transactions.

Note: The farewell part of the email has been ignored, as per the given rules.