Update SWC-120.md

entries/docs/SWC-120.md

@@ -1,3 +1,15 @@
+# Please note, this content is no longer actively maintained.
+
+The content of the SWC registry has not been thoroughly updated since 2020. It is known to be incomplete and may contain errors as well as crucial omissions.
+
+For currently maintained guidance on known Smart Contract vulnerabilities written primarily as guidance for security reviewers, please see the
+[EEA EthTrust Security Levels specification](https://entethalliance.org/specs/ethtrust-sl). As well as the latest release version, an
+[Editor's draft](https://entethalliance.github.io/eta-registry/security-levels-spec.html) is available, 
+that represents the latest work of the group developing the specification.
+
+General guidance for developers on what to consider to ensure security, that is currently maintained, is also available through the 
+[Smart Contract Security Verification Standard (SCSVS)](https://github.com/ComposableSecurity/SCSVS).
+
 # Title
 
 Weak Sources of Randomness from Chain Attributes
@@ -23,6 +35,11 @@ Ability to generate random numbers is very helpful in all kinds of applications.
 - [When can BLOCKHASH be safely used for a random number? When would it be unsafe?](https://ethereum.stackexchange.com/questions/419/when-can-blockhash-be-safely-used-for-a-random-number-when-would-it-be-unsafe)
 - [The Run smart contract](https://etherscan.io/address/0xcac337492149bdb66b088bf5914bedfbf78ccc18)
 
+### EEA EthTrust Security Levels Specification
+
+- [**[M] Sources of Randomness**](https://entethalliance.org/specs/ethtrust-sl/#req-2-random-enough)
+- [**[M] Document Special Code Use**](https://entethalliance.org/specs/ethtrust-sl/#req-2-documented)
+
 ## Samples
 
 ### guess_the_random_number.sol