Vis.js - set graph label's font as underline

I use vis.js to display a graph. I want to use markup on the node's label. I'm using a node of type text.

What I did:

I set font option in the node option:

// in the option object
nodes: {
    type: 'text'
    font: {
        multi: 'html',
    }
}

And I added the  tag to my label

// in the option object or node data object
label: `<u>${YourLabel}</u>`

Result: My label is displayed with the  tag on the graph. As mentioned in this post, this works for  and .

Is  not supported ?

Solution

According to issue 3119 in the old vis.js, only ,  and <code> is supported:

With respect to HTML, the following is possible: Set option node.font.multi: html. This allows you to use the ,  and <code> tags within the label text for formatting.

In the current version of vis.js, it looks like that is still the case - from LabelSplitter.js:

// Hash of prepared regexp's for tags
var tagPattern = {
  // HTML
  '<b>': /<b>/,
  '<i>': /<i>/,
  '<code>': /<code>/,
  '</b>': /<\/b>/,
  '</i>': /<\/i>/,
  '</code>': /<\/code>/,
  // Markdown
  '*': /\*/,  // bold
  '_': /\_/,   // ital
  '`': /`/,   // mono
  'afterBold': /[^\*]/,
  'afterItal': /[^_]/,
  'afterMono': /[^`]/,
};

Styling node content with SVG (where  can work) is shown here but there are warnings about browser support and this formats node content, not the node label.