I am a beginner, so most of this is new to me. Any help is greatly appreciated.

This is from the beginning of Shine on you Crazy Diamonds by Pink Floyd.

17b(19)r17p15

I know the b means to bend to a 19, but what does the r mean? I can't recall seeing one before. So my question is ... "How do I play this short little riff?"

Thanks for the help