Descriptions of each record class, what they contain, details of finding aids, how and why these records were created, can be found in the catalogue. To get to these descriptions, click on The Catalogue then enter letter code and series number in the top left box where it says: Go to reference. The next page will reveal the context of the originating Office records, which division created this record and what these pieces contain. An example is WO 363/A 127 which are records created by the War Office, service records of World War I soldiers, the “A” is for soldiers with the last name beginning with A on piece 127. After the context description is a record summary. This gives the dates covered in this series and their availability to the public. If you would like to find the exact piece for the alphabetical listing of a particular surname enter the reference again in the box titled "browse from this reference." This will open a description of all surnames in each piece. Many of these service records are in the online digitized collection.