diff --git a/docs/persistent-identifiers.rst b/docs/persistent-identifiers.rst
--- a/docs/persistent-identifiers.rst
+++ b/docs/persistent-identifiers.rst
@@ -174,12 +174,15 @@
 
 Where:
 
-- ``<path_absolute_escaped>`` is the ``<path_absolute>`` in `Section 3.3 of RFC
-  3986 <https://tools.ietf.org/html/rfc3986#section-3.3>`_, where all
-  occurrences of ``;`` and ``%`` have been percent-encoded (as `%3B` and `%25`
-  respectively)
-- ``<url_escaped>`` is a RFC 3987 compliant URL, where all occurrences of ``;``
-  and ``%`` have been percent-encoded (as `%3B` and `%25` respectively)
+- ``<path_absolute_escaped>`` is an ``<ipath-absolute>`` from `RFC 3987`_, and
+- ``<url_escaped>`` is a `RFC 3987`_ IRI
+
+in either case all occurrences of ``;`` (and ``%``, as required by the RFC)
+have been percent-encoded (as ``%3B`` and ``%25`` respectively). Other
+characters *can* be percent-encoded, e.g., to improve readability and/or
+embeddability of SWHID in other contexts.
+
+.. _RFC 3987: https://tools.ietf.org/html/rfc3987
 
 
 Semantics