Subject: [salud] The consequences of alert-indications with two labels

From: [email-masked] (Dale R. Worley)
Date: Thu, 14 Feb 2013 16:04:31 -0500 (EST)

(as an individual)

There are a two standard alert-categories which have alert-indications
that consist of two labels.  The examples I find are:

    urn:alert:service:recall:*
    urn:alert:locale:country:*

(I do not list <private-name>, because all categories include private
names, and we have specified how <private-name>s are to be handled in
various situations.)

This allows us to construct the syntactically correct but undefined
URNs:

    urn:alert:service:recall
    urn:alert:locale:country

The question I am discussing here is whether there will be a problem
if a UA specifies one of these URNs -- Will this prevent the receiving
UA from making sensible renderings?

In regard to the rules of section 8.1, I do not see any difficulty.
The interpreting UA will not recognize the URN, and will attempt to
remove the final label.  That eliminates the alert-indication
entirely, and the URN will be discarded from interpretation.

In regard to the non-normative algorithm of section 9, let us take
<urn:alert:locale:country> as an example:  This URN specifies the
"country" node in the "locale" tree, which is a child of the root
node.  We assume that there are no signals that are positioned at that
node, although locale-specific signals are positioned at child nodes
of the "country" node, and all other signals are positioned at the
root node:

                    urn:alert:locale:country
                       |
                       V
    locale-----+----country----+----ad      	  
    DEFAULT     	       |    RING-ANDORRA   
    PRIORITY-HIGH	       |			  
    CALL-WAITING               +----de    
    ...                        |    RING-GERMANY
                	       |			  
                               +----us
                                    RING-US
	                  
Then the processing of <urn:alert:locale:country> would cause all
signals to be eliminated from the set of signals that are considered
for rending if they are not positioned at the root node of "locale".
This is the same effect as would happen from a URN for an unknown
locale, such as <urn:alert:locale:country:es>.

This discussion convinces me that there is no difficulty with the
rules and algorithms if we define two-label alert-indications, and
thus make it possible to construct URNs that have no meaning.

Do other people agree?

Dale