It is easy to enable the external identifier which is a field that can be used for anything external that you would like to add to the matter details. An example would be a firm that has Manor for all things electronic but also has a system of physical boxes to store physical data related to their matters. In that case you would like to add the box number to the matter details. This is very easy.

Lets start by enabling the external identifier. Navigate to Administration and then Settings. Find the External identifier area and switch the setting to on. 

You can insert your own field label. For this example lets use the name "Box number". Then just hit Save and your are done.

To see the field in action you can now navigate to any single matter. Once there you will see a new field in the matter details.

Now I know that in physical box number 56 I can find physical data related to Matter number 1 in Manor.

You can also see a new column in the list of all matters. Now you can sort your matters by the external identifier or use the quick-filter to find a specific matter based on the identifier.

Pro tip: You can also use the universal search to find matters by the external identifier.

Can I have multiple external identifiers?

Yes and no. Yes you enter many values in the field. Say you have two boxes related to the matter then you could type "56, 57" into the field and it would work fine and no you can not have a totally different set of external identifiers with another name at this point.