It seems that it misses the link to the ‘Inform - Support - Patches - DM4 misprints’ in if-archive : http://www.ifarchive.org/indexes/if-archiveXinfocomXcompilersXinform6Xmanuals.html You can only find it in http://inform-fiction.org/patches/misprints.html
There is an error in the DM4 about the return value of the fonction PronounValue():
Which is incorrect. PronounValue() returns:
nothing, if the pronoun does not esiste.
NULL, if the pronoun is not set (not nothing like the documentation says)
The Object, if the pronoun is set.