OK How's this:- Number by itself "3" Draw
                Number with >    "3>" Blow
                Each apostrophe "3'" Half step bend
                Sharp sign       "3#" Overblow
                Tilde            "3~" Dip bend
                Ampersand between numbers "3&4" play simultaneously
                Slash between numbers    "3/4" slur
                percent before numbers    "%3" tongue slap

               2 percents before numbers "%%3" flutter tongue
                A vertical bar seperates measures
               lower case v denotes Vibrato.
               All tabs in first position unless otherwise stated.
I myself will not often use some of these symbols as I wish to contribute stuff beginners can use but I believe it is a workable system: )