[SpamCop-List] Re: 3d
John E. Malmberg
wb8tyw at qsl.network
Sat Sep 11 00:23:29 EDT 2004
> What does putting 3d in htlm links do for spammers? I know they use it to
> avoid link detection, but how and why does it work? Why does the HTML code
> continue to work?
If you look closely, you will see an equals "=" sign in front of it.
That format is known as quoted printable, which is a way to encode
characters in mail and news postings.
E-mail and news groups are based on a 7bit ASCII code, and in the past,
some gateways and modems will only pass 7bit ASCII.
So if you want anything else to get through, you have to encode it.
The code "equal_sign"3D in quoted printable translates to an equals
sign, so that is how the URL still works.
Some e-mail clients will translate quoted printable codes in spite of
the message not stated that it is encoded that way.
Spammers take advantage of that in attempts to avoid content filters,
and possibly the spamcop parser.
There are also errors in some implementations of quoted printable, and
errors in some mailing list software that decodes it, so you may see
extra equals signs in e-mails and news postings as a result of that.
Now what is not commonly known is that some modems that claimed to be
9600 baud modems before the 9600 baud standard was established actually
only send that effective rate for 7 bit ASCII. They use data
compression, with bit eight to indicate that the data compression was in
The uncompressed data rate was 2400 baud.
To send a real eight bit character, they sent two characters.
So for plain ASCII text, you got your 9600 baud.
Try to transfer a binary file, it went at 1200 baud.
And it was almost impossible to convince many programmers to use the
standard 2400 baud modem pools instead for time critical file transfers
instead of these proprietary 9600 baud modems. They would not even look
at where the owner's manual clearly stated that binary transfers went at
an effective rate of 1200 baud.
Of course the only thing that these "9600" baud modems had been
purchased for was for binary file transfers, back when 1200 baud was the
highest standard. All those decisions had been done before I came to
wb8tyw at qsl.network
Personal Opinion Only
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