The plain text of Domesday Book is full of pitfalls for the unwary. If a place was the subject of successive entries, for instance, it was usually named only on its first occurrence. In subsequent entries, a phrase like 'in the same vill' was used. A search for that place on the plain text would therefore retrieve only the first of the series of entries.
Similarly, landholders become simply 'he' after being named in the first of a sequence of entries. Worse still, structural features of the text - counties, Hundreds, or tenants-in-chief - may be implied but not named in scores or even hundreds of successive entries. On the largest fief in Domesday, held by the Conqueror's half-brother, Bishop Odo of Bayeux, the bishop is named as tenant-in-chief only eight times on his 225 manors. This situation is not uncommon. Searches on the plain text of Domesday may therefore produce highly misleading results.
To rectify this, the implied meaning has been inserted into the text wherever this is unambiguous. Such insertions are transparent to the user though they may be made visible by customising the text. Searches will normally take account of such insertions, though the user may also specify searches on the unimproved text by excluding text insertions from a search specification.
Insertions have also been made to incorporate material from other Domesday sources, notably the Domesday satellite texts. The majority of these insertions are identifications of landowners named only by their christian names in Domesday Book itself but supplied with identifying bynames, patronymics, or titles in other sources. These insertions may be identified as a group, or according to the particular satellite text from which they are derived. Insertions from the satellites may be viewed or searched but the user may also revert to the plain text by using the appropriate codes when specifying a search.
Finally, where plausible identifications for people or places have been suggested by historians, these have been incorporated, with identifying codes which allow them to be disregarded if necessary.
For the use of codes in searching the text, see properties and property searching.