Book: Login Module Reference Revision: n_1575841_login-module-reference_version_6.4_edition_1.0_release_0-revision_6701191 Section: 2.2. UsernamePasswordLoginModule Issue description: 1) For exactness there should be rather mentioned fully-qualified name (FQN) which is org.jboss.crypto.digest.DigestCallback in sentence "The class name of the DigestCallback implementation that includes pre/post digest content like salts for hashing the input password. " 2) Description of digestCallback option for UsernamePasswordLoginModule contains sentence "Only used if hashAlgorithm has been specified.". However it also depends on hashUserPassword option which has to be set to true. Suggestions for improvement: Replace description with "The class name of the org.jboss.crypto.digest.DigestCallback implementation that includes pre/post digest content like salts for hashing the input password. Only used if hashAlgorithm has been specified and hashUserPassword is set to true."