From d1f22f7de71b71ff35b7cbcc0f6e810cbe4ceb25 Mon Sep 17 00:00:00 2001
From: Ricky Atkins <ricky.atkins@daltonmaag.com>
Date: Mon, 25 Nov 2024 13:32:05 +0000
Subject: [PATCH] Document logic

---
 Lib/ufo2ft/featureWriters/markFeatureWriter.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Lib/ufo2ft/featureWriters/markFeatureWriter.py b/Lib/ufo2ft/featureWriters/markFeatureWriter.py
index dc1b24be..9542baba 100644
--- a/Lib/ufo2ft/featureWriters/markFeatureWriter.py
+++ b/Lib/ufo2ft/featureWriters/markFeatureWriter.py
@@ -746,6 +746,8 @@ def includedInClass(gdefClass: Optional[Set[str]], glyphName: str) -> bool:
                 if not anchor.isContextual:
                     continue
 
+                # See "after" truth table for what this logic hopes to achieve:
+                # https://github.com/googlefonts/ufo2ft/pull/890#issuecomment-2498032081
                 if anchor.number is not None and includedOrNoClass(
                     ligatureClass, glyphName
                 ):