If perchance you're curious to actually see what/where it was that I wanted to turn ligs off (and why), it was for this book of mine...
https://www.mobileread.com/forums/sh....php?p=3419678
I just uploaded a newly-revised version of it -- at least, the "revision" is that I spent these last few years learning type design, and now my book has my own fonts (5 of 'em!) used in it.
It's right in the main title that I wanted to turn off ligs, so that the long-"s" + "t" doesn't turn into the ligature for that. My code for that heading (with my tiny space kludge) is this...
Code:
<h1 class="large red sigil_not_in_toc" style="margin-top:0; margin-bottom: 0.14em; line-height:100%;"><i> Laſ<span style="font-size:0.000001em; line-height:10%;"> </span>t Folio.</i></h1>
You don't even have to trouble yourself to download the book if you want to see how that looks -- in the screenshots I provided in the post, one is of the title page, where you'll see in the main title, where it says "Laſt Folio," the long-"s" + "t" does NOT come out as a lig (as it otherwise would).
Wish I could just turn the ligs off temporarily in some easy way -- but oh well, perhaps the solution I came up with will help someone else out somehow, too.