How do you format a Gmail's body via URL parameters?

Question

I have written a small web application that allows a user to email the details of a work order via Gmail. I use a floating action button that opens a new tab with the Gmail compose url below:

https://mail.google.com/mail/?view=cm&fs=1&tf=1&source=mailto&to=" + ReceiverString + "&su=" + SubjectString + "&body=" + BodyString + "&shva=1

So in my case, some of the work order details are in BodyString. I want to be able to bold some words if possible. For example,

BodyString = <b>Work Order ID:<b> 5738

and then it be bold within the actual email. I have used Ctrl+B to bold things within Gmail and then inspected it to check if it was actually using <b> tags and it was. I figure it's some sort of security thing with including tags in an email, but does anyone know of any alternative to achieve this?

For reference, here is a working link to the compose window.

Answer 1

This is not possible as per RFC 6068

The special "body" indicates that the associated is the body of the message. The "body" field value is intended to contain the content for the first text/plain body part of the message. The "body" pseudo header field is primarily intended for the generation of short text messages for automatic processing (such as "subscribe" messages for mailing lists), not for general MIME bodies.

See here for a similar SO question.