eBay search fail

[Fred Cisin]

On Tue, 1 May 2018, Noel Chiappa via cctalk wrote:
> I'd previously noticed that searches for 'pdp-11' turned up things with
> 'pdp11' in the title, so they apparently internally drop the '-'. (Google
> does a similar thing.) I just tried, and searching for '"pdp-11"' (i.e. exact
> multi-word match, which I use for '"Digital Equipment"') still turns up
> 'pdp11' items. Case ('PDP-11' versus 'pdp-11') doesn't seem to matter
> either.

hyphen "-" seems to do three different things in eBay search system:
1) as a literal character, where there IS a hyphen in the term
(which might simply always be ignored)

2) as a negation ("minus sign" V "hyphen"), to mean exclude, but only when 
delimited (following a space)
Do some current computer character sets have discrete hyphen and 
minus-sign?

2) as a marker for consecutive terms, ignoring intervening space
DEC-RAINBOW
is the same to eBay as:
"DEC RAINBOW"       /* quotation marks actually in search term */
DEC RAINBOW
DECRAINBOW

but NOT the same as:
RAINBOW DEC
DEC COMPUTER RAINBOW

So,
PDP-11
"should" match:
PDP11
PDP 11
PDP-11