Available since Jenkins 2.335.
View the complete list of symbols available to use on GitHub
Jenkins Symbols are an extensive and consistent collection of icons for use in Jenkins and plugins. Symbols are intended to be used everywhere a traditional icon would be used, such as in the sidebar, in buttons and in tables. Symbols are scalable, support different weights and adapt to the user’s theme.
Read more about symbols and how to use them in your plugin on the design library documentation page.