Add (dummy) rationale to questionable check

com.google.fonts/check/family/equal_unicode_encodings
On the Open Type Profile.

Note: we may simply deprecate, as we're not sure why would we expect what it checks.

(PR #4570)

CHANGELOG.md

@@ -30,6 +30,7 @@ A more detailed list of changes is available in the corresponding milestones for
   - **[com.google.fonts/check/xavgcharwidth]:** Added rationale. Also, when glyphs needed to compute xAvgCharWidth are missing, it is considered critical, so it is now results in a FATAL-level result. (PR #4570)
   - **[com.adobe.fonts/check/fsselection_matches_macstyle]:** Improve log messages to include the bit values. (PR #4570)
   - **[com.google.fonts/check/fsselection]:** Added rationale. (PR #4570)
+  - **[com.google.fonts/check/family/equal_unicode_encodings]:** Added rationale, even though this is a questionable check, which we may simply deprecate, as we're not sure why would we expect what it checks. (PR #4570)
 
 
 ## 0.12.0a2 (2024-Feb-21)

Lib/fontbakery/checks/opentype/cmap.py

@@ -6,6 +6,11 @@
 @check(
     id="com.google.fonts/check/family/equal_unicode_encodings",
     proposal="legacy:check/013",
+    rationale="""
+    Ensures that all format 4 cmap tables in a family have the same unicode
+    encoding.
+"""  # Sure, this is more a description than a rationale. I don't actually
+    # know why we want to ensure this.
 )
 def com_google_fonts_check_family_equal_unicode_encodings(ttFonts):
     """Fonts have equal unicode encodings?"""