Information about your upcoming marriage and witnesses
You will also have to provide information about the intended marriage, such as:

Whether it will be a civil, secular or religious ceremony
The intended date and location of the marriage
Details of the proposed solemniser of the marriage
The names and dates of birth of the 2 proposed witnesses
A PPS number is required for all parties serving notice of intention to marry, who have or will have a current or a future address within the State

- https://www.citizensinformation.ie/en/birth-family-relations...

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Note added at 15 mins (2024-01-17 11:24:30 GMT)
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Irish Marriage Records

Dates: From 1845 (Protestant marriages), from 1864 (Roman Catholic marriages)

Cost of copy: €20.00 certificate (plus postage)

Comments: Marriage records in the GRO are cross-listed under the surname of both the bride and groom. Be sure to request a "full certificate" or a photocopy of the original marriage record, which contains the date and place of marriage, names of bride and groom, age, marital status (spinster, bachelor, widow, widower), occupation, place of residence at time of marriage, name, and occupation of father of bride and groom, witnesses to marriage and clergyman who performed the ceremony.

After 1950, additional information provided on marriage records includes the dates of birth for the bride and groom, mother's names, and a future address. - https://www.thoughtco.com/ireland-vital-records-1422818