Some letters have multiple versions, like subtle shape changes, smoother connections, or just a little extra personality. Contextual alternates automatically swap in the best-looking version based on the letters around it. It keeps the font from looking repetitive or awkward.
If you want the font to do its thing, turn these on. If you would like to use the original character set for Birdie (or any other font with these features) turn them off)
In Adobe programs, this lives in the OpenType panel.
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Photoshop
Stylistic sets are like alternate outfits for your lettering. Different forms or attitudes you can switch on by choice.
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