I just started reading Programming As If People Mattered by Nathaniel Borenstein.
To start chapter 5, Nathaniel relates this story about TECO, an “infamously powerful but hard-to-use line editor…”:
As you probably know, TECO is a line editor in which all of the commands are control characters. To enter some text you would type control-a, followed by the text, and a control-d to end the text. When I was first learning TECO I decided to type in a ten-page paper. I typed control-a, followed by all ten pages of text, followed by the control-d. Unfortunately, as I was typing in the paper I must have hit another control character. So when I typed the final control-d I received the message: ‘Unknown control character–input ignored.’ An hour of typing down the drain.
If that sounds like amusing but ancient history, recall in RSSOwl and Feed Validation a single errant control character in an RSS feed makes RSSOwl refuse the entire feed.
The date of the TECO story isn’t reported but TECO was invented in 1963. (Wikipedia has a nice article, TECO (text editor))
Fifty (50) years later we are still struggling with a sensible responses to errant control characters in data feeds?
Are you filtering non-valid control characters from RSS feeds?
Or are you still “current,” circa 1963?