Holy fuck , what a hatefilled asshole dad is . <| sep |> That ' s complete bullshit . It ' s an echo chamber at best . If you dissent you are blocked . Period . <| sep |> QR codes are not limited . You can do codes 110 rowlet to whatever as many times as you like . Just can ' t repeat a code in the same round . Does that answer your Q ? <| sep |> Great Seller ! Quick Response ! Will do business in the future ! <| sep |> Suck a dick <| sep |> love it ! !!<| sep |> There ' s a lot of overlap with technical typesetting , and you could usefully mine that literature . I picked up a lot through exposure to LaTeX and the surrounding community of people who care a lot about beautifully typesetting documents , technical and non . Practically , most of the details of how to handwrite such symbols are learned by watching what happens on the blackboard , on transparencies , and similar handwritten resources produced by an instructor things like using R with doublestruck vertical bar to represent the reals , rather than a blackletter R and which has since spread to typeset text using the mathbb style , for blackboard math .