[aprssig] DIGI Overlay Characters

[Robert Bruninga]

> I am not on top of the meanings of the various symbols.  
> Perhaps someone else can help with that.

"S" is a fully modern New-N Paradigm digi
 - Supports WIDEn-N
 - Traps larger values of N
 - Supports SSn-N paths within an SS or SSS.. Region
 - Beacon format shows capabilities: "W2,SSn-N..."
 - Supports Local Info FREQ object in its Btext

"N" is an old N digi -often- with these problems:
 - Beacon rate is not proportional: 10min dir, 30min 2 hops
 - does not identify digi type with APNxxx destination address
 - Does not trap large values of N
 - Does not indcate capabilities in its beacon
 - Does not use new standard FREQ object format
 
"1" Is a modern WIDE1-1 only fill-in digipeater

"1" Can also indicate an enforced one-hop digi such as in the LA
basin.  It will trap all WIDEn-N packets and only produce one
hop.

"P" is a PACCOM digi that supports New-N.  It will only do
W11,W22,W21,W33.

The following are obsolete:
"W", "T", "R", "U".  Others?

Notice that a UIDIGI ROM can fully support the New-N paradigm so
it becomes a "S" but because it will have APNUxx in its
destination field, we can still identify the type of digi..

If I omitted any, then lemme know and I will re-release this
email.  The point being, that New-N is SELF IDENTIFYING OF ITS
CAPABILITIES TO ALL USERS.  That way we can know what works,
what doesn't and what needs to be fixed.  And users in an area
can see exactly what they will get.

Bob, WB4APR