Hello,
The syntax is as follow:
.re<customToolName>:before {
content: "\iconnumber" !important;
}
For example if the tool name is custom2 and you'd like to apply the bold font icon over it use this class:
<style>
.reCustom2:before {
content: "\e601" !important;
}
</style>
as shown in the example below
Regards,
Rumen
Progress Telerik