PHP is SERVER SIDE script, it do not have code for blinking text. It is HTML code. The code is <blink>text</blink>
You should know that blinking text REALLY bothers people browsing a website. I recommend avoiding it at all costs.
The <blink> element is not part of the HTML specification. You can use CSS text-decoration: blink (not supported by IE) I think blinking is annoying and recommend to not use it.