diff --git a/programs/svm-spoke/src/instructions/deposit.rs b/programs/svm-spoke/src/instructions/deposit.rs
index da118d2b1..df785a132 100644
--- a/programs/svm-spoke/src/instructions/deposit.rs
+++ b/programs/svm-spoke/src/instructions/deposit.rs
@@ -1,3 +1,8 @@
+// Note: The `svm-spoke` does not support `speedUpV3Deposit` and `fillV3RelayWithUpdatedDeposit` due to cryptographic
+// incompatibilities between Solana (Ed25519) and Ethereum (ECDSA secp256k1). Specifically, Solana wallets cannot
+// generate ECDSA signatures required for Ethereum verification. As a result, speed-up functionality on Solana is not
+// implemented. For more details, refer to the documentation: https://docs.across.to
+
 use anchor_lang::prelude::*;
 use anchor_spl::token_interface::{Mint, TokenAccount, TokenInterface};