0 1 2 3 4 5 6 7 8 9 A B C D E F — how ugly mixing letters and digits together like that. In order to remain consistent with the 10 decimal digits that are independent from the alphabet, we really need 6 more digit-like characters for hexadecimal numbers. To this end I have been considering what these digits should look like. Having some resemblance to the letters A-F or their lowercase equivalents is clearly desirable but not essential. Using the forms of existing digits so they look in place seems reasonable, so long as the digits are clearly distinguishable from each other.

Suggestively B (eleven = 8 + 3) looks like its octal representation 13. F (fifteen = 8 + 7 = octal 17) looks like a mirrored 7 crossed in the european style. If we munge 1 and 5 together the result looks kind of like a D or a d with a decoration on top (D = thirteen = 8 + 5 = octal 15). So we have the basis of character representation for hexadecimal digits taking its inspiration from octal — very nice.

To express A, C and E in terms of octal 12, 14 and 16 requires a greater suspension of disbelief (a facility in which I personally excel).

If you rotate a digit 2 around its vertical axis and add a short stem on the bottom you end up with an ankh (cf the Ankh-Morpork coat of arms). This is a very fortuitous symbol and just so happens to start with the letter A. I think that the ankh an excellent symbol to represent this much preferred number (ten = 8 + 2 = octal 12).

C (twelve = 8 + 4 = octal 12) will give us much more trouble. It’s hard to superimpose reflected or rotated versions of the digit 4 without yielding and unreadable mess. I have abandoned any attempt to do so and have chosen to represent C directly with a bar through it in the style of the symbol for cents. Hexadecimal numbers and representation a purely decimal currency would never be found together so this doesn’t present any possibilities of confusion.

E (fourteen = 8 + 6 = octal 16) is also troublesome. There is plenty of opportunity of forming interesting conjunctions of 1 and reflected and rotated versions of 6, but none are obviously superior to the others. I copped out and chose a reflected version of ‘B’ which has the virtue of looking a great deal like a barred curvy E à la ESSO. A euro currency symbol might also work here.