From In-Portal User Manual

A label has the following fields:

• Phrase Id - this field is a read-only, unique and internal system language phrase ID.
• Label - this field contains the system name of the language phrase. This name is used in all templates, and in some settings. For visual convenience, all labels to be used on the front-end start with the prefix 'lu_', and all labels to be used in the administrative console start with the prefix 'la_'. The administrator may use their own conventions for naming the labels, however it is recommended to follow this naming rule to keep the regional pack compatible with the ones produced by Intechnic Corporation.
• Value - this field contains the label value in the local language of the pack. That is where the translation goes.
• Phrase Type - this field designates whether the label is to be used in the front-end, or in the administrative panel, or in both. Unlike the prefix of the label, this field must be set properly, as it drives the caching mechanism. There are two ways to edit multiple labels at once. The first way is to edit one label, and then to use the blue Previous and Next buttons to go back and forth between the labels. The same order as in the list will be used in this case. The second way is to select multiple labels at once, and click the edit button. As with any other second-level list, it is very important to remember, that your changes are not actually saved, until the regional package is saved. If you make changes to the labels, and then move to a different section without hitting Save on the regional package level, your changes will be lost.