What are the present criteria for the encoding of characters that have been fairly recently invented please?

What are the present criteria for the encoding of characters that have been fairly recently invented please? There seems to be a lack of clarity.
 
For example, the criteria in relation to Wingdings and Webdings in the following document are not the same as that often stated on the Unicode mailing list for the encoding of characters that have been fairly recently invented: the mailing list conventional wisdom being that significant usage using a Private Use Area encoding must first have been achieved.
 
http://std.dkuug.dk/jtc1/sc2/wg2/docs/n4085.pdf
 
quote
 
Indicators for such benefit for the user can be:
– Evidence of actual use.
– Evidence of prevention of an otherwise probable actual use due to the lack of encoding.
– Conformance with or compliance to another standard.
 
end quote
 
The concept of benefit to the user and the concept of that benefit being indicated by evidence of prevention of an otherwise probable actual use due to the lack of encoding seems to me to be a progressive policy.
 
William Overington
 
17 August 2011
 
Received on Wed Aug 17 2011 - 12:14:33 CDT