diff --git a/docs/persistent-identifiers.rst b/docs/persistent-identifiers.rst
--- a/docs/persistent-identifiers.rst
+++ b/docs/persistent-identifiers.rst
@@ -4,7 +4,7 @@
 SoftWare Heritage persistent IDentifiers (SWHIDs)
 =================================================
 
-**version 1.5, last modified 2020-05-14**
+**version 1.6, last modified 2021-04-12**
 
 .. contents::
    :local:
@@ -228,6 +228,24 @@
 maintained in future versions of this scheme (or Git).
 
 
+Automatically fixing invalid SWHIDs
+-----------------------------------
+
+User interfaces may fix invalid SWHIDs, by removing leading or trailing characters
+inserted by user error (such as a trailing slash, caused by copy-pasting one character
+too many from a ``https://archive.softwareheritage.org/`` URL).
+
+User interfaces should show an error when such an automatic fix occurs,
+so users have a chance to fix their SWHID before pasting it to an other interface
+that does not perform the same corrections.
+
+Finally, implementations should take great care not to accidentally correct
+a valid SWHID (eg. the ``origin`` qualifier's value may end with a slash);
+for example by checking if a SWHID exists before fixing it.
+APIs should not attempt to fix SWHIDs, to avoid silent changes (or even corruptions)
+in the middle of data processing pipelines.
+
+
 Examples
 ========