diff --git a/crypto/ecdsa/doc.go b/crypto/ecdsa/doc.go
index 1cdc9da..c2fccc5 100644
--- a/crypto/ecdsa/doc.go
+++ b/crypto/ecdsa/doc.go
@@ -1,7 +1,9 @@
 /*
 Package neofsecdsa collects ECDSA primitives for NeoFS cryptography.
 
-Signer and PublicKey provide corresponding interfaces from neofscrypto package.
+Signer and PublicKey support ECDSA signature algorithm with SHA-512 hashing.
+SignerRFC6979 and PublicKeyRFC6979 implement signature algorithm described in RFC 6979.
+All these types provide corresponding interfaces from neofscrypto package.
 
 Package import causes registration of next signature schemes via neofscrypto.RegisterScheme:
   - neofscrypto.ECDSA_SHA512