In American English quotations are often used to mark something as not-quite-the-truth. There's even a blog where we point out mis-used quotations: http://www.unnecessaryquotes.com/

example: Today I "talked" to my brother. (But I actually just instant-messaged him.)

edit: crap, I may have just misread your comment, did you mean </flame> to be like a </sarcasm> tag? Regardless, you were downvoted by others, so I thought I should help explain since you're foreign.

You should also consider advertising the conference as: "php-ist Istanbul: Now with extra watercannon!"