[aprssig] spaces in object names

[Curt, WE7U]

On Thu, 13 Aug 2009, Dave Skolnick wrote:

> If as quoted the APRS spec says "An Object Report has a fixed
> 9-character Object name, which may consist of any printable ASCII
> characters" then there is in fact no significant ambiguity. Since no
> reference documents are listed in the APRS spec the definition of
> "printable ASCII characters" is dependent on common usage.

I disagree with "no reference documents are listed", as the mention
of "ASCII" is in fact a reference to a standards document called
"American Standard Code for Information Interchange".


> As
> noted earlier the ANSI specification for ASCII is very clear on the
> matter. A space is a printable character.

There 'ya go then...


> If we can agree on that, at least for purposes of discussion, the next
> interesting phrase is "fixed 9-character Object name." To me, that
> says the true Object name should be padded with spaces (or with
> something) to fill out the nine character specification.

For transmit purposes or for parsing received Object packets I think
we all agree with that because the spec is very clear there.  It's
what we do after we receive it and how we manipulate it in the
software that's up in the air a bit.


> The fact that some people have misinterpreted the spec (not supporting
> case sensitivity is a good example) doesn't justify a change. Consider
> all the effort going to bring station and digipeater configurations
> into compliance with the spec - the argument for compliance with the
> spec loses credibility if there is a change to the written spec to
> align with any one (or more) particular "as-built" application.

Amen!  But that brings other spec changes to mind which I'd better
not bring up here else it'll turn into the "1001 things to do with a
dead cat" sort of thread (never-ending)!


> If it were me I would add a reference section that includes the ANSI
> spec for ASCII and incorporate by reference with the caveat that in
> the case of a discrepancy between the APRS spec and a reference
> document the APRS spec applies.

This might cause the "printable space" discussion to pop up every
few years.  Better to put it to rest now, but agree with the words
above as well.


> With respect to the possible confusion between Rescue 1 (one space)
> and Rescue  1 (two spaces), I suggest that it be left up to the
> clients to choose how to show Object names to minimize confusion AND
> to the various tactical organizations to establish their own policies.
> Just because APRS supports Object names with embedded spaces doesn't
> mean an organization has to take advantage of the capability.

Maybe force fixed larged fonts on everybody so they can count
characters...  hi hi  (just kidding!)

I'm for letting the user decide whether to use multiple spaces or
other repetitive or repetitive-looking chars.  Some pop-up warning
message if S/W can catch a few typical problem areas wouldn't be a
bad idea either as long as it didn't prevent the user from using the
available tools to best effect for their application.

-- 
Curt, WE7U.                         <http://www.eskimo.com/~archer>
    APRS:  Where it's at!                    <http://www.xastir.org>
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