This override process involves merging all message files of the same name according to a precedence order. The order is based on the SERVER_COMPONENT_ORDER environment variable. This environment variable contains a comma separated list of component names: the left most has the highest priority, and the right most the lowest.
SERVER_COMPONENT_ORDER=custom,Appeal,ISProduct,sample
The order in Customizing a Message File, shows that the precedence of Appeal is higher than that of the sample component. The core component always has the lowest priority and as such does not need to be specified. Any components that are not specified are placed alphabetically above core and below those that are specified.
When merging message files, the components listed in the SERVER_COMPONENT_ORDER are taken in order of highest to lowest priority. In Customizing a Message File message files from the sample component are merged with the message files located in the core component. The message files from ISProduct are then merged into the intermediate results and the merge process continues until the messages in the custom component are merged.