span.tag-rev:before {
    content: 'v';
}

span.tag-rev {
    display: inline-block;
    background-image: linear-gradient(to top, rgb(20, 120, 0), rgb(80, 255, 0));
    padding: 0 0.3em;
    margin: 0.2em;
    color: white;
    border-radius: 0.3em;
}

span.rev-dev:before {
    content: 'v';
}

span.rev-dev {
    background-image: linear-gradient(to top, rgb(120, 20, 0), rgb(205, 100, 0));
}

span.rev-dev:after {
    content: ' (in development)';
}