Just wanted to add my support to Audrey's answer and to add a bit about citing references to GRO (English/Welsh) certificates.
There are now two versions of the GRO index.
- The contemporary handwritten/typeset/computer-generated indexes which were compiled up to 1983 in quarterly volumes and from 1984, in annual volumes. These were compiled by clerks at the GRO from the quarterly returns submitted by the local registration system.
- The GRO's own online index, launched in 2016, which was compiled from the GRO's own copies of the certificates.
Because of this, the two do not represent an exact match.
The original contemporary indexes have been digitised and 're-indexed' on a number of websites, including:
The index references up to 1983 are, however, to all intents and purposes, identical:
Note that the latter includes the mother's maiden name - a detail which was NOT shown in the 'original' indexes until 1911.
In both cases, the full GRO reference comprises the following elements:
Year of registration
Quarter of registration - usually shown either as MAR, JUN, SEP, DEC
or Q1, Q2, Q3, Q4
This reference is the only 'correct' way to cite a GRO certificate. The certificates themselves don't have a reference - all we have is the reference shown in the index so these ARE official references.
After 1984 an entirely different referencing system was adopted which I will attempt to describe in another answer. This one is long enough!