[RTTY] WHY put CQ at the end?

[iw1ayd - Salvatore Irato]

Hi all.
My calling schema, if not forced by rules, is:
{ENTELF}TEST IW1AYD IW1AYD CQ {RX}{ENTERLF}
That's a way to say I am ready and calling,
It's the same for my QSO closing schema:
{ENTELF}UT5EPP TU IW1AYD CQ {RX}{ENTERLF}

1)
During the WPX, a very poor SOSB 15m experience, I saw my call somewhat 
changed to anything else.
Often I'd see W1AYD or something not so exotic for me. Usually from EU 
skimmers, usually from the same, but not the only, EU skimmer during a 
discrete amount of time. I'd deleted the wrong entry in the bandmap but 
it went in agn and agn with the same or different changes. A marginal 
signal from me, it could be.
Near me there was another friend calling with the same schema but with a 
shorter call and doing  40m SOSB.
I'd saw his call, IW1QN, mangled with some letters added at the end.
Often the changes on ours call signs appeared twice, with different errors.

2)
As noted by others I'd also saw, when S&P on multi - a lot of those in 
WPX, that several of  the multipliers had already gone.
In minutes I mean. So this is probably the effect of the

TEST CALL1 CALL1 CQ CALL2 CALL2

The same should be taken in account with

TEST CALL1 CALL1 CQ CALL3 CALL3

As there where often more than 3/4 call on the same QRGs at the same time.

The spread of the arbitrary offsetting of QRG could help a little bit 
looking at the bandmap, isn't? But it's not enough.

MORE ..
I and Federico, IW1QN, used only DL4RCK as the cluster, with a 20 
minutes period of refresh.
I didn't see the DUPE rate increasing by those observed factors.  An 
amount variable from 10 to 20 QSO over one thousand isn't that much of 
dupes.
But anyway dupes doesn't exists ... everybody is welcome. The rate of 
second callers that doesn't respond to the TU NOW is worse.
As far as I remember this is the first time on witch I'd see those 
effects, 1 & 2,  that much. Maybe it was also in the Roundup but not before.

That's my set of notes on the subject matter. I have no conclusion at 
this time. Hope that somebody other will enlighten to me about those 
findings.
It's also far from my knowledge if a RTTY skimmer runs it's detections 
schema on a continue string or could be able to fragment the data stream 
in a logical way.
Not taking in account what's into a sliding window but what could have 
more considerably a common sense for humans. Not that easy for software.

              73 de iw1ayd Salvo