None of those is important. The Fifth definition is the one you want. TBR Tallboy.
You: Writer, hopeful or successful, tired of being a reader, tentatively moving toward being a writer...
TBR Tallboy: TBR Tallboy, a hip, low-tech, chapbook style fiction 'zine, successful after only one issue, filled with stories from atrociously talented writers, if I do say so myself.
You: Eagerly submitting, for fame and fortune, if not monetary compensation.
TBR Tallboy: DEADLINE: SEPTEMBER 30th, don't miss it.
You: Wishing to read TBR, Issue 1, holding up a fiver, eagerly waiting for the mail.
You & TBR Tallboy. It's a match.
That is all.