diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5a62c38..7d36d52 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -40,8 +40,9 @@ replacement, and each removed path, column or flag.
   `misc.territory` does not ship, Antarctica's among them, and the constant `UTC`
   are gone. It draws from 401 zones where it drew from 27 common ones, and evenly,
   so a bare `misc.timezone` now renders a sub-zone such as `America/Indiana/Knox`
-  far more often than a capital's: select inside a territory, or pin the zone. `misc.useragent` is the top-user-agents desktop and mobile lists with
-  `browser`, `device` and `os` columns. `misc.car` keeps its makes and models, with
+  far more often than a capital's: select inside a territory, or pin the zone.
+  `misc.useragent` is the top-user-agents desktop and mobile lists with `browser`,
+  `device` and `os` columns. `misc.car` keeps its makes and models, with
   `misc.car.maker` renamed `misc.car.make`.
 - `geo.SE` and `geo.US`: five linked tables per country, `region`, `municipality`,
   `locality`, `postal-code` and `street`, weighted by population and address counts
diff --git a/README.md b/README.md
index 350c6a8..fb704ae 100644
--- a/README.md
+++ b/README.md
@@ -172,9 +172,9 @@ carries `car`, `coordinate`, `creditcard` (Luhn-valid), `currency` (ISO 4217),
 name, so they are drawn from rather than selected in.
 [`DATA-LICENSES.md`](DATA-LICENSES.md) names each table's source and licence.
 
-`misc.timezone` is every zone tzdb gives a shipped territory — 401 of them, from one
-apiece for most to 29 for the US — with the territory's code and the zone's standard
-offset, not the offset in force on any given date, which a zone name is what you
+`misc.timezone` is every zone tzdb gives a shipped territory, from one apiece for
+most of them to dozens for the largest, with the territory's code and the zone's
+standard offset, not the offset in force on any given date, which a zone name is what you
 store precisely to avoid. It links to `misc.territory`, so `misc.territory[SE].timezone`
 is `Europe/Stockholm` and a drawn territory and zone agree. `misc.useragent` carries
 `browser`, `device` and `os` beside the string, and `misc.car` a `make` and a `model`.
diff --git a/data-import/timezone.py b/data-import/timezone.py
index 947f370..c1b1a8c 100644
--- a/data-import/timezone.py
+++ b/data-import/timezone.py
@@ -27,9 +27,12 @@ REGIONS = ["africa", "antarctica", "asia", "australasia", "backward", "etcetera"
 
 def member(tar, name):
     try:
-        return tar.extractfile(name).read().decode("utf-8")
+        f = tar.extractfile(name)
     except KeyError:
-        sys.exit(f"{name}: the tarball no longer holds it; the tzdb layout has moved")
+        f = None
+    if f is None:
+        sys.exit(f"{name}: the tarball no longer holds it as a file; the tzdb layout has moved")
+    return f.read().decode("utf-8")
 
 
 def offsets(tar):
diff --git a/data-import/useragent.py b/data-import/useragent.py
index 5cfc436..5262d93 100644
--- a/data-import/useragent.py
+++ b/data-import/useragent.py
@@ -19,8 +19,7 @@ SOURCE = "https://raw.githubusercontent.com/microlinkhq/top-user-agents/master/s
 OUT = Path(__file__).resolve().parent.parent / "data" / "misc" / "useragent.tsv"
 CACHE = Path(__file__).resolve().parent / "cache"
 COLUMNS = ["browser", "device", "os", "ua"]
-# First match wins: every Chromium fork carries Chrome's token too, so one this list
-# does not name would ship as Chrome rather than be dropped.
+# First match wins: a Chromium fork this list does not name ships as Chrome.
 BROWSERS = [("Edge", r"Edg(A|iOS)?/"), ("Opera", r"OPR/"), ("Samsung Internet", r"SamsungBrowser/"),
             ("Chrome", r"(Chrome|CriOS)/"), ("Firefox", r"(Firefox|FxiOS)/"), ("Safari", r"Version/[\d.]+ .*Safari")]
 SYSTEMS = [("iOS", r"iPhone|iPad|CPU OS "), ("Android", r"Android"), ("ChromeOS", r"CrOS"),