[tz] [PATCH 3/4] Update column 4 definition

[J William Piggott]

* zone1970.tab: Update the column 4 definition, adding that global regions
  are now part of the criteria.

Signed-off-by: J William Piggott <elseifthen at gmx.com>
---
 zone1970.tab | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/zone1970.tab b/zone1970.tab
index c1b9222..19e2157 100644
--- a/zone1970.tab
+++ b/zone1970.tab
@@ -18,7 +18,8 @@
 #     Please see the 'Theory' file for how zone names are chosen.
 #     If multiple zones overlap a country, each has a row in the
 #     table, with each column 1 containing the country code.
-# 4.  Comments; present if and only if a country has multiple zones.
+# 4.  Comments; present if and only if a country has multiple zones
+#     within the same global region (first segment of column 3).
 #
 # If a zone covers multiple countries, the most-populous city is used,
 # and that country is listed first in column 1; any other countries