say which churches are missing, and why, instead of guessing them

Ten of the fourteen Byzantine-rite Eastern Catholic churches are absent. The
honest reason is that their calendars could not be verified: general
references do not record whether the Slovak, Hungarian, Krizevci,
Italo-Albanian, Greek, Bulgarian, Macedonian, Belarusian, Russian or Albanian
churches keep Pascha with Rome or with the local Orthodox, and the churches'
own sites render their liturgical calendars in JavaScript. Inferring it from
geography would put an unsourced claim in the one place this program exists to
be right about.

Nobody needs an entry to get a correct calendar, though, and both --list and
the README now say so: one question to a parish picks one of the three
reckonings, which between them cover every combination there is.

README.md

@@ -174,6 +174,29 @@ See [the law and the fast](#the-law-and-the-fast-are-not-the-same-question)
 for what `--typikon` does with this, which is the flag most Byzantine Catholics
 will want.
 
+### The other ten
+
+There are fourteen Byzantine-rite Eastern Catholic churches. The Slovak,
+Hungarian, Krizevci, Italo-Albanian, Greek, Bulgarian, Macedonian, Belarusian,
+Russian and Albanian ones are **not** here, and the reason is worth stating:
+their calendars could not be verified against anything published. General
+references do not record them, and the churches' own sites render their
+liturgical calendars in JavaScript. Guessing from geography would put an
+unsourced claim in the one place this program is actually for.
+
+You do not need an entry to get a correct calendar. Ask your parish one
+question, and the answer picks a reckoning:
+
+| is Pascha kept with… | and the fixed feasts… | |
+|---|---|---|
+| Rome | on the civil calendar | `--calendar western` |
+| the local Orthodox | on the civil calendar | `--calendar new` |
+| the local Orthodox | thirteen days behind | `--calendar old` |
+
+Add `--tradition slavic` or `--tradition greek` for the usage your books
+follow. A patch adding your church, with a source for its calendar, is
+welcome.
+
 ## The fast
 
 Six levels, ordered from strictest to laxest. They are the Typikon's own

src/main.rs

@@ -149,6 +149,17 @@ fn list_jurisdictions() {
         }
         println!();
     }
+    println!("  Not listed? There are fourteen Byzantine-rite Eastern Catholic");
+    println!("  churches and ten of them are not here, because their calendars");
+    println!("  could not be verified against anything published. Ask your parish");
+    println!("  one question: is Pascha kept with Rome or with the local");
+    println!("  Orthodox? The answer picks a reckoning above:\n");
+    println!("    with Rome, fixed feasts on the civil calendar   --calendar western");
+    println!("    with the Orthodox, fixed feasts on the civil     --calendar new");
+    println!("    with the Orthodox, fixed feasts thirteen days    --calendar old");
+    println!("                                                     behind\n");
+    println!("  A patch adding your church, with a source for its calendar, is");
+    println!("  welcome.\n");
 }
 
 fn elide(text: &str, width: usize) -> String {