Circular Gallifreyan is a fan created alphabet and all credit for its creation goes to BlackHatGuy. This reference sheet, by itself, will be of little use unless you understand how to write in CG already. While a similar reference is available in the official guide, I have created this updadetd version to include the recently added one-dot and discouraged four-dot letters, as well as the more comprehensive vowel layout previously posted by The Creator.
While my preference has been to list the letters in order of number of lines, I realize some prefer the alphabetical ordering from the guide. If you are one of these people, check out this version.
I would like to note that the description for punctuation was modified from the official guide to include the community supported option for hyphens to connect to a word in the same manner as an apostrophe. It has also been accepted that that such punctuation can extend from the word to the inner sentence circle rather than the outer, supporting the first line, "Punctuation is attached to the inner sentence circle" as opposed to the details for the exception of punctuation lines being contained between the inner and outer sentence circle. In spite of this, I have left the original wording stating that they extend to the outer sentence circle.