Tags are one of the primary sources of metadata in Image Relay. There are two ways to go about adding Tags to your system. The first way is to go to Admin Metadata Tools and hit "Create New Tag Set." You will then need to name your set and can add as many Tags manually as you would like below. The second way to upload is with a CSV file. 

How to Upload in Bulk

If you have hundreds of Tags, or have been taking your time to think about your Tags and organize them in a spreadsheet, you can upload them with a CSV file. The CSV file must be formatted so that your Tag Set name is in the first column, and your Tags go to the right horizontally. Note that your Tag Set name is not a Tag itself, just a way to group the Tags. Here is an example: 

The sheet cannot contain any special characters including the following: / \ & <> ( ). It also cannot contain any hard returns. It must be exported from Excel or Google Sheets as a CSV file. </>

To upload the file go to Admin Metadata Tools Tag Sets. Then hit the "Import" button and you will be promoted to choose a file. You will receive an email letting you know if the the upload was successful or if there were errors. 

Further Resources:
Creating and Using a Controlled Vocabulary with Tag Sets
Metadata and Tagging Features on Image Relay Plans