How to Read a Record of Service or Casualty Form (First World War)
The entries appearing on these documents are taken from unit Part II Orders. The Orders are the administrative directives concerning the movement of individuals into and out of each unit for various reasons, such as leave, hospitalization, and transfer to and from another unit, as well as changes in financial or ration allowances, or punishment awarded for service offences.
Each unit of the Canadian Expeditionary Force issued these orders on a regular basis, and they are collected in our holdings and arranged by unit and date in Record Group (RG) 150, Series 1. However, each entry for an individual mentioned in the orders is placed separately on his personnel record, with a reference to the order number in which the original entryappears (see remarks column on the image).
Note: The terms taken on strength (TOS) or struck off strength (SOS) refer to the movement of personnel into and out of a unit. They are usually entered in pairs in an individual's personnel records, recording the departure from one unit and the entry into another, and the dates on which they occurred.