TAB is good but...

I love MuseScore, great for piano notation. I also love that there is the ability to use guitar tab but there seems to be a lot missing. I can't use it until I figure out how to notate a slide.

How can I notate a slide in (from below and from above) using guitar TAB?

Thanks, keep up the good work!!

John Carson
P.S. I would rather use MuseScore but currently have to use Guitar Pro 8 for Tab (it's incredibly intuitive!)