In Northern Ireland and County Donegal, the Ulster dialect (Gaedhilg Uladh) is used extensively alongside the standard form as the spoken language in primary and secondary schools.
When Taoiseach Éamon de Valera instigated a new constitution, which was adopted in 1937, he established a committee to propose spelling reforms for the "popular edition" of the Irish-language text.
[nb 1] The committee was unable to agree, but one member, T. F. O'Rahilly, sent his notes to de Valera, who forwarded them to Rannóg an Aistriúchán, which developed a system circulated within the civil service in 1945 and revised in 1947.
On the other hand, national TV and radio stations have increased certain types of mixing between the dialects in recent decades, reducing the differences.
The standard is described by Mícheál Ó Siadhail as being "to an extent based on a 'common core' of all Irish dialects, or the most frequent forms, and partly on random choice".
For example, while pre-Caighdeán Irish had separate spellings for the three words "bay" (bádh), "sympathy" (báidh), and "drowning" (bádhadh), the Caighdeán replaced all three by bá.