Check a .udc section multiplier against the list the file names

MultWindowType names the list N1MM validates a received section against,
and every exchange that was not all digits counted as a multiplier here.
Four of N1MM's lists are held now -- the ARRL sections, the US states,
the Canadian provinces and the 165 OK/OM districts, which came out of
N1MM's own exe -- and a file naming one of them counts only the values
on it. A file naming any of the hundred-odd others keeps the old rule.

The 2023 OK/OM DX log now scores contact for contact as N1MM did. Two
contacts in the 2026 log still differ: the district code is stored with
a trailing space, which N1MM matches against its list untrimmed, so it
counts no multiplier where this counts one.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01RoGtneMQaz4M9w7Kk49AVD

src/Nonemm.Contests/Multipliers/OkOmDistricts.cs

@@ -0,0 +1,26 @@
+namespace Nonemm.Contests.Multipliers;
+
+/// The 165 district codes the OK/OM DX contest exchanges. N1MM keeps the same
+/// list in its admin database under the name `OKOMDX`, which is the name a
+/// `.udc` file gives in `MultWindowType`.
+public static class OkOmDistricts
+{
+    public static readonly IReadOnlySet<string> All = new HashSet<string>(StringComparer.OrdinalIgnoreCase)
+    {
+        "APA", "APB", "APC", "APD", "APE", "APF", "APG", "APH", "API", "APJ", "BBE",
+        "BBN", "BKD", "BKH", "BKO", "BMB", "BME", "BNY", "BPB", "BPV", "BPZ", "BRA",
+        "CBU", "CCK", "CJH", "CPE", "CPI", "CPR", "CST", "CTA", "DCH", "DDO", "DKL",
+        "DKV", "DPJ", "DPM", "DPS", "DRO", "DSO", "DTA", "ECH", "ECL", "EDE", "EJA",
+        "ELI", "ELO", "ELT", "EMO", "ETE", "EUL", "FCR", "FHB", "FHK", "FJI", "FNA",
+        "FPA", "FRK", "FSE", "FSV", "FTR", "FUO", "GBL", "GBM", "GBR", "GBV", "GHO",
+        "GJI", "GKR", "GPR", "GTR", "GUH", "GVY", "GZL", "GZN", "GZS", "HBR", "HFM",
+        "HJE", "HKA", "HNJ", "HOL", "HOP", "HOS", "HPR", "HSU", "HVS", "BAA", "BAB",
+        "BAC", "BAD", "BAE", "MAL", "PEZ", "SEN", "DST", "GAL", "HLO", "PIE", "SEA",
+        "SKA", "TRN", "BAN", "ILA", "MYJ", "NMV", "PAR", "PBY", "PRI", "PUC", "TNC",
+        "KOM", "LVC", "NIT", "NZA", "SAL", "TOP", "ZMO", "BYT", "CAD", "DKU", "KNM",
+        "LMI", "MAR", "NAM", "RUZ", "TTE", "TVR", "ZIL", "BBY", "BRE", "BST", "DET",
+        "KRU", "LUC", "POL", "REV", "RSO", "VKR", "ZAR", "ZIH", "ZVO", "GEL", "KEA",
+        "KEB", "KEC", "KED", "KEO", "MIC", "ROZ", "SNV", "SOB", "TRE", "BAR", "HUM",
+        "KEZ", "LEV", "MED", "POP", "PRE", "SAB", "SLU", "SNI", "STR", "SVI", "VRT",
+    };
+}

src/Nonemm.Contests/Multipliers/SectionLists.cs

@@ -0,0 +1,21 @@
+namespace Nonemm.Contests.Multipliers;
+
+/// The lists N1MM checks a received section against, by the name a contest's
+/// `MultWindowType` gives. N1MM holds well over a hundred of them in its admin
+/// database; the ones here are the lists this program already has, plus the
+/// OK/OM districts.
+///
+/// A name with no list gives null, and the caller then counts whatever the
+/// operator typed.
+public static class SectionLists
+{
+    public static IReadOnlySet<string>? For(string multWindowType) =>
+        multWindowType.Trim().ToUpperInvariant() switch
+        {
+            "SECTION" => ArrlSections.All,
+            "STATE" => StatesAndProvinces.AllStates,
+            "PROVINCE" => StatesAndProvinces.Provinces,
+            "OKOMDX" => OkOmDistricts.All,
+            _ => null,
+        };
+}

src/Nonemm.Contests/Udc/UdcMultipliers.cs

@@ -1,3 +1,4 @@
+using Nonemm.Contests.Multipliers;
 using Nonemm.Core;
 
 namespace Nonemm.Contests.Udc;
@@ -17,6 +18,7 @@ public sealed class UdcMultiplier
     private readonly IReadOnlyList<string> onlyFor;
     private readonly IReadOnlyList<string> notFor;
     private readonly IReadOnlyList<string> onlyForSections;
+    private readonly IReadOnlySet<string>? sections;
 
     public UdcMultiplier(int index, UdcFile file, UdcMultiplierScope shared)
     {
@@ -32,6 +34,7 @@ public sealed class UdcMultiplier
         onlyFor = file.List($"CountMultOnlyFor{suffix}");
         notFor = file.List($"DoNotCountMultOnlyFor{suffix}");
         onlyForSections = file.List($"CountMultOnlyForSec{suffix}");
+        sections = SectionLists.For(file.Text("MultWindowType"));
     }
 
     public bool IsDefined => source.Length > 0;
@@ -127,16 +130,24 @@ public sealed class UdcMultiplier
 
     private static string Upper(string text) => text.Trim().ToUpperInvariant();
 
-    /// A section multiplier ignores a value that is all digits. N1MM checks the
-    /// received exchange against the section list the contest names, and a file
-    /// whose section column also carries the serial numbers the other side of
-    /// the contest sends — OK/OM DX SSB is one — would otherwise count every
-    /// serial number as a multiplier. The section lists themselves are not held
-    /// here.
-    private static string? SectionName(string text)
+    /// A section multiplier counts only a value on the list `MultWindowType`
+    /// names, which is what N1MM checks it against. Without a list — this
+    /// program holds four of N1MM's, and N1MM has over a hundred — anything
+    /// that is not all digits counts, so a file whose section column also
+    /// carries the serial numbers the other side of the contest sends — OK/OM
+    /// DX SSB is one — does not count every serial number as a multiplier.
+    private string? SectionName(string text)
     {
         string section = Upper(text);
-        return section.Length > 0 && section.All(char.IsAsciiDigit) ? null : section;
+        if (section.Length == 0)
+        {
+            return null;
+        }
+        if (sections is not null)
+        {
+            return sections.Contains(section) ? section : null;
+        }
+        return section.All(char.IsAsciiDigit) ? null : section;
     }
 
     private static string? LastLetter(string call)