Hey! I've seen a few people who have some trouble with the HTML tags on their profiles, so i thought I could just share what i know!

Intro

Use '<tag>' to surround the tags below, and at the end of the text or whatever, you put </tag> to end the formatting

Lesson one: Text Tags

The primary tags you're probably going to be using are tags that create text. By default, any text on your profile will be text just like this: plain text. 

If you use <h1>-<h4> before and after text, it will create larger text.

This is h1

This is h2

This is h3

This is h4

Lesson two: Text modifier tags

Some other tags you'll be using are called Modifier tags, or Mod tags. By default, any text on your profile will be either black, or if you're using a layout, a different color. There are ways to change the color and font of any text on your profile.

These tags are formatted like so:<h1 style="">Your text here</h1>. and the modifier tags would go inside the double quotes. Some examples of mod tags include:

color:

What this tag does is fairly self-explanatory.  It changes the color of the text. 

Here is the full list of all the color names.

background-color:

This is also fairly self-explanatory. It makes there a background color behind the text. The above color list works for this as well.

border:2px solid

This places a 2 pixel border around your text. You can obviously change the size, color, etc. 

font-family:

This changes what font your text is in. 

This is an example of another font.

Here is a list of fonts you can use!

font-size: 100%

This changes the font size of your text. By default, it is set to 100% but you can make itbigger,

bigger,

or smaller!

by changing the percentage! The first is 175% and the second is 60%.

Conclusion

This is by no means a comprehensive list, just what i know! I hope that i was able to help you out! Have fun, and experiment with these to find your favorite setup, size, or font! Good luck customizing your profile!