EDIT Tree Alphabet Ogham, pronounced OH-am or OH-yam, is a script that was used to create Gaelic inscriptions in Celtic Ireland and Britain. Ogham was mainly used to inscribe names on stones (and sometimes wood) as territorial markers and gravestones. It is also known as the tree-alphabet because its letters are named after trees and plants which were sacred by the druids of these times. Not all of them are known tree names today. There are three different lists (called a Bríatharogam) of kennings (figures of speech) connected to the names of the trees.

There is an old Irish manuscript on Ogham (»In Lebor Ogaim«, the book of Ogams) listing about 100 different secret modes of writing Ogham. 92 of them are listed in the Book of Ballymote (Leabhar Bhaile an Mhóta), an old Irish manuscript, a page of which can be seen on the right.

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EDIT History and legend Phonological evidence shows that the alphabet predates the 4th century. It was mainly used in the 5th and 6th century around the Irish sea. Presumably, Ogham was modeled after another script, probably the Latin, which was the prevalent script in this area around the 4th century. Some people think it may have been the Elder Furthark (see Runic U+16A0) which would account for the letters »H« and »Z« that aren’t used in Irish, and explain the existance of both »U« and »W«, a distinction that is not made in Latin and Greek writing.

According to the medieval Irish Book of Ballymote (writen 1391), Ogham was invented by Ogma (or Ogmius) sun-face, the Gallic god of eloquence. In Gallic artwork, his golden speech was shown as a gold chain connecting the tip of his tongue to the ears of the listeners. According to the book, Ogham was invented when Ogma »raised four pillars of equal length«. The characters of the alphabet where then etched onto these pillars.

The Ogham alphabet is also known as »beth luis nion«, a word which is constructed out of the first, second and fifth letter of this alphabet, thus equivalent to the origin of the word alphabet itself.

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EDIT Writing Ogham is written »like a tree grows«, meaning the writing starts at the bottom of a stone, then goes upward. The characters are etched onto the edge of the stone, the vertical line or center line they are connected with when written on paper (or shown in the Unicode charts) represents this edge. Most of the etchings are found on ancient standing stones and begin at the bottom left corner, crossing the top of the stone and going down its right side in case of longer inscriptions. A newer way of writing (after the 6th century), known as »scholastic«, is created just on the face of the stone.

The structure of the alphabet mirrors the legendary origins of its being etched onto four pillars, its twenty characters (feda) are organized in four series (aicmí, plural of aicme, »family«). These series are named after their first character and contain different strokes:

1. Aicme Beithe (B-group), downward strokes (letters B,L,F,S,N)
U+1681(Beith) - U+1685 (Nion)

2. Aicme hÚatha (H-group), upward strokes (letters H,D,T,C,Q)
U+1686 (Uath) - U+168A (Ceirt)

3. Aicme Muine (M-group), perpendicular strokes (letters M, G, NG, Z, R)
U+168B (Muin) - U+168F (Ruis)

4. Aicme Ailme (A-group), notches (vowels, letters A, O, U, E, I)
U+1690 (Ailm) - U+1694(Iodhadh)

The Ogham Feather Mark (U+169B) marks the beginning of a text, the Ogham Reverse Feather Mark (U+169C) marks its end.

A list with with variant names of the letters found in various publications, and names of the associated plants can be found on the website of Curtis Clark.

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EDIT Ogham and Unicode The standardization of the spelling of the letternames is not only conform to the Unicode Standard but is also used in the Irish Standard 434:1999 and stems from 1997.

The characters U+1681 - U+1694 are traditional letters, U+1695-U+169A are supplementary letters (Forfeda), the others are punctuation.

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