-# An S/MIME [RFC1847] signed message with a zero-length body. This attri-
-# bute is to be stored and requested in binary form, as
-# 'userSMIMECertificate;binary'. It contains the person's entire certifi-
-# cate chain and the signed attribute that describes their algorithm capa-
-# bilities, stored as binary data. If available, this attribute is
+# A PKCS#7 [RFC2315] SignedData, where the content that is signed is
+# ignored by consumers of userSMIMECertificate values. It is
+# recommended that values have a `contentType' of data with an absent
+# `content' field. Values of this attribute contain a person's entire
+# certificate chain and an smimeCapabilities field [RFC2633] that at a
+# minimum describes their SMIME algorithm capabilities. Values for
+# this attribute are to be stored and requested in binary form, as
+# 'userSMIMECertificate;binary'. If available, this attribute is