There are two manuscript indexes to the Registry of Deeds on microfilm at the Family History Library, 1708-1929 (FHL) and an ongoing indexing project online. Understanding these indexes is your key to this valuable set of records.
The “Surname Index” (Grantor Index) is alphabetical by first letter of the seller’s name. This is a limitation as deeds are usually a tangle of owners, lessors and sub-lessors. It is arranged by time periods. Another limitation is that it does not identify the county or townland of the property until after 1833.
The “Lands Index” (County Index) is arranged geographically. The handwriting can be terrible or the quality of the microfilming problematic. This index is currently only way to access all registered transactions for a specific place.
The Lands Index is divided by county, Corporation Town, time period with townlands listed by first letter. From 1828 the County Index divides entries by barony within a county. From 1828, the cities and Corporation Towns are listed separately. From 1832, the year of registration is given in the index.
The Lands Index lists volume, page and memorial number of the transaction. Once you have the reference, then you are ready to examine the deed books on microfilm at the FHL.
The “Registry of Deeds Index Project Ireland”: http://freepages.genealogy.rootsweb.ancestry.com/~registryofdeeds is an online index being compiled by volunteers. The purpose of the project is to index all of the names that appear in the memorial books at the Registry of Deeds. This includes wills and marriage settlements. The index can be searched by name, grantor, family name and memorial number.
Deed index research can be tedious, but it is a necessary evil in comprehensive Irish genealogy.