DataSift's filtering engine ignores all mentions of Twitter users in Tweets. Therefore, it would see this Tweet:
If you like @DataSift you have to follow @DataSiftNews and @DataSiftDev every day.
If you like you have to follow and every day.
Of course, this means that you cannot write a CSDL filter like this to look for mentions of @DataSift:
twitter.text contains "DataSift" or twitter.text contains "@DataSift"
Instead, use the twitter.mentions target:
twitter.mentions contains "DataSift" // Notice that there is no need to include the @ symbol
URLs within Tweets are also invisible to the filtering engine. DataSift sees this Tweet:
If you like @News surf to http://nytimes.com.
If you like surf to.
Consequently, you cannot write a CSDL filter like this one for URLs:
twitter.text contains "nytimes.com"
Instead, use a Links Augmentation target:
links.domain in "nytimes.com"