Wiktionary:About Old Irish

Defining the language
Wikipedia defines Old Irish (ISO 639-3 sga) as the Goidelic language used between the 6th and 10th century AD. Earlier forms – primarily the Ogham inscriptions – are considered to be Primitive Irish rather than Old Irish by scholars, and should be labeled with the ISO 639-3 code pgl.

The border between Old Irish and Middle Irish is not particularly clear, and defining the difference between the two is made no easier by the fact that a large number of manuscripts were written during the Middle Irish era but in a language that was already archaic at the time. Certainly everything in the Thesaurus Palaeohibernicus can be considered Old Irish. In addition, words appearing in the Félire Óengusso (the poem itself, not in the Middle Irish preface, glosses and notes) can usually safely be labeled "Old Irish".

The  (labeled in DIL as "Laws i", "Laws ii", and "Laws iii") and the Book of Aicill (labeled in DIL as "Laws iii" since it was published together with part of Senchas Már in one volume) can safely be labeled as "Old Irish" as well. But watch out: the texts in Ancient Laws of Ireland are copied and edited from very late manuscripts (many scribe-induced misspellings and poor grammatical forms will appear), and also are infested with commentary made after the Old Irish period! Fortunately, Ancient Laws of Ireland prints out commentaries as tinier text and the Old Irish portions in large text. If DIL marks a Laws citation with the word "Comm.", it is usually not old.

The Dictionary of the Irish Language includes not only Old Irish words, but also Middle Irish and Early Modern Irish words, so it's important to look at the attestations given in a lemma to decide what era the words belong to. It cannot be assumed that everything in that dictionary is Old Irish. Put any Middle Irish words and forms in a "Middle Irish" section and put any Early Modern Irish words under "Irish".

Thurneysen (R:sga:Thurneysen) covers only Old Irish, so words discussed there can usually be assumed to be Old Irish, unless he specifically describes them as late or Middle Irish forms. Matasović (R:cel:EDPC) clearly labels terms as Old Irish or Middle Irish and so can be used as a guide. If in doubt, it is safer to label a term Middle Irish since most Old Irish words will be also found in Middle Irish texts, but not vice versa.

Lemmas
Since Old Irish has no standardized spelling, for convenience we generally use the spelling of the Dictionary of the Irish Language (online at http://www.dil.ie/) as the primary spelling (unless there are good reasons to use some other spelling as the primary one), and list other attested spellings as alternative spellings, using Template:alternative spelling of. The lemma form of verbs is the 3rd person singular present indicative, independent form (i.e. absolute form of simple verbs like, deuterotonic form of complex verbs like ).

The diphthongs should be spelled with $⟨áe aí óe oí⟩$, not with $⟨ái ói⟩$. The latter spellings are reserved for followed by a palatalized consonant.

Proper nouns should be lemmatized with initial capital letters even if the manuscripts do not actually use capital letters with these nouns.

Many Old Irish vowel-initial words are frequently spelled with a silent h in old manuscripts, especially very short words that would be only one or two letters long without the h. At Wiktionary, the spelling without the h is preferred as the lemma. Links and references to the preposition may link to but using link label functions to display  in order to keep using the standard spelling.

The raised dot (·) is used to show the "joint" of the verbal complex, i.e. it is placed before the stressed syllable. It is also placed at the beginning of prototonic and conjunct verb forms used in isolation (e.g. ·marb, ·tabair) to distinguish them from deuterotonic and absolute forms (e.g. marbaid, do·beir). However, the raised dot is not used in the names of pages. Thus the page for do·beir is called dobeir. (This parallels Wiktionary's approach to Latin and Old English, where macrons are used in display but not in page titles, and for the same reason: the raised dot in Old Irish is a pedagogical aid that did not appear in actual Old Irish writing.)

Of the diacritics, the acute accent is included in page names (thus and  are distinct), as it is fairly regularly represented in manuscripts. But the punctum delens and the dieresis are not: sceïd is at and muccḟoil is at.

The language module knows to remove the raised dot, dieresis, and punctum when they are used inside a template identifying the language as Old Irish, so links like,  , and   will correctly point to [[dobeir]], [[sceid]], and [[muccfoil]].

io- and iā-stem nouns and adjectives should be lemmatized to end in -(a)e even if the nominative singular is unattested or its DIL headword ends in -a.

What an entry should include
WT:ELE is the general guide to entry layout. Old Irish entries should follow that guide; sections that are especially to be remembered are "Alternative forms" (since Old Irish has so many of them!) and "Descendants", where the Middle Irish, modern Irish, Scottish Gaelic, and Manx descendants of the word should be listed.

Old Irish pronunciation is often rather speculative, but if pronunciation information is included, be sure to add sga as the first positional parameter of the template. This will create a link to Appendix:Old Irish pronunciation, where our conventions for the phonemic representation of Old Irish are given.

Verb conjugations may be shown by means of the conjugation-table templates and. For nouns, there are several declension-table templates listed at Category:Old Irish noun inflection-table templates. For mutations, use sga-mutation.

When creating a new entry for an Old Irish word, remember to create links to it too. The "Translations" section of the corresponding English word should include a line for Old Irish (indented below the line for Irish), and the entries for the modern Goidelic descendants should include an "Etymology" section that links to the Old Irish word.

Appendices and templates
See Category:Old Irish appendices and Category:Old Irish templates.