diff --git a/core/domain/src/main/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntry.kt b/core/domain/src/main/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntry.kt
index a16b6853..67c66bff 100644
--- a/core/domain/src/main/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntry.kt
+++ b/core/domain/src/main/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntry.kt
@@ -46,6 +46,12 @@ object GridEntry {
 
     /** Worth mentioning but not worth refusing. */
     enum class Warning {
+        /**
+         * Two characters. Legal per ADIF, but a field is 20 by 10 degrees - close to useless for a
+         * satellite contact, so it is worth saying rather than refusing.
+         */
+        FIELD_ONLY,
+
         /** Four characters, so the location is only accurate to about 100km. */
         SQUARE_ONLY
     }
@@ -81,7 +87,14 @@ object GridEntry {
         if (upper[0] !in FIELD_RANGE || upper[1] !in FIELD_RANGE) {
             return Verdict.Unusable(Reason.FIELD_OUT_OF_RANGE)
         }
-        if (!upper[2].isDigit() || !upper[3].isDigit()) {
+        // ASCII digits only. Char.isDigit() is Unicode-aware and covers the whole Nd category, so
+        // it accepted Arabic-Indic, Devanagari and fullwidth digits - which a localised keypad can
+        // produce without the operator seeing any difference. ADIF 3.1.7 defines Digit as "an ASCII
+        // character whose code lies in the range of 48 through 57", and Wavelog stores GRIDSQUARE
+        // verbatim, so such a value would never match a real grid in any statistics query.
+        // Guarded on length: a 2-character locator has no square pair, and reading index 2 of it
+        // would throw.
+        if (text.length >= SQUARE_LENGTH && (!upper[2].isAsciiDigit() || !upper[3].isAsciiDigit())) {
             return Verdict.Unusable(Reason.SQUARE_NOT_DIGITS)
         }
         if (text.length >= SUBSQUARE_LENGTH) {
@@ -89,27 +102,42 @@ object GridEntry {
                 return Verdict.Unusable(Reason.SUBSQUARE_OUT_OF_RANGE)
             }
         }
-        if (text.length == EXTENDED_LENGTH && (!upper[6].isDigit() || !upper[7].isDigit())) {
+        if (text.length == EXTENDED_LENGTH && (!upper[6].isAsciiDigit() || !upper[7].isAsciiDigit())) {
             return Verdict.Unusable(Reason.SQUARE_NOT_DIGITS)
         }
 
         return Verdict.Acceptable(
             normalised = normalise(upper),
-            warning = if (text.length == SQUARE_LENGTH) Warning.SQUARE_ONLY else null
+            warning = when (text.length) {
+                FIELD_LENGTH -> Warning.FIELD_ONLY
+                SQUARE_LENGTH -> Warning.SQUARE_ONLY
+                else -> null
+            }
         )
     }
 
     /** `OL72ap` - upper case field, digits, lower case subsquare, as the convention renders it. */
     private fun normalise(upper: String): String = buildString {
-        append(upper.take(SQUARE_LENGTH))
+        append(upper.take(minOf(upper.length, SQUARE_LENGTH)))
         if (upper.length >= SUBSQUARE_LENGTH) append(upper.substring(4, 6).lowercase())
         if (upper.length == EXTENDED_LENGTH) append(upper.substring(6, 8))
     }
 
+    /** ADIF 3.1.7 defines Digit as ASCII 48-57. Kotlin's isDigit() is far wider. */
+    private fun Char.isAsciiDigit(): Boolean = this in '0'..'9'
+
+    private const val FIELD_LENGTH = 2
     private const val SQUARE_LENGTH = 4
     private const val SUBSQUARE_LENGTH = 6
     private const val EXTENDED_LENGTH = 8
-    private val VALID_LENGTHS = setOf(SQUARE_LENGTH, SUBSQUARE_LENGTH, EXTENDED_LENGTH)
+
+    /**
+     * ADIF 3.1.7: GRIDSQUARE takes "2-character, 4-character, 6-character, or 8-character" locators.
+     * A 10 or 12 character locator stores its first 8 here and the rest in GRIDSQUARE_EXT, which
+     * neither WavelogQso nor Wavelog's own field list carries - so the extra pair has nowhere to go
+     * and the UI clips at 8, which produces the spec-correct GRIDSQUARE value.
+     */
+    private val VALID_LENGTHS = setOf(FIELD_LENGTH, SQUARE_LENGTH, SUBSQUARE_LENGTH, EXTENDED_LENGTH)
     private val FIELD_RANGE = 'A'..'R'
     private val SUBSQUARE_RANGE = 'A'..'X'
 }
diff --git a/core/domain/src/test/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntryTest.kt b/core/domain/src/test/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntryTest.kt
index 96f1530e..679dc583 100644
--- a/core/domain/src/test/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntryTest.kt
+++ b/core/domain/src/test/java/com/rtbishop/look4sat/core/domain/wavelog/GridEntryTest.kt
@@ -80,6 +80,49 @@ class GridEntryTest {
         assertEquals("OL72ap", (GridEntry.check("  OL72AP  ") as GridEntry.Verdict.Acceptable).normalised)
     }
 
+    /**
+     * Two characters is legal per ADIF, so it is accepted - but a field is 20 by 10 degrees, close
+     * to useless for a satellite contact, so it says so rather than refusing.
+     */
+    @Test
+    fun `a two character field is acceptable with a warning`() {
+        assertEquals(
+            GridEntry.Verdict.Acceptable("OL", GridEntry.Warning.FIELD_ONLY),
+            GridEntry.check("ol")
+        )
+    }
+
+    /** A 2-character entry must not read past its own end. */
+    @Test
+    fun `a two character field does not crash`() {
+        for (grid in listOf("AA", "RR", "ol", "FN")) {
+            assertTrue(GridEntry.check(grid) is GridEntry.Verdict.Acceptable)
+        }
+    }
+
+    /**
+     * Kotlin's Char.isDigit() is Unicode-aware and accepted Arabic-Indic, Devanagari, Persian and
+     * fullwidth digits, which a localised keypad produces without the operator seeing a difference.
+     * ADIF 3.1.7 defines Digit as ASCII 48-57, and Wavelog stores GRIDSQUARE verbatim, so such a
+     * value would never match a real grid in any statistics query.
+     */
+    @Test
+    fun `non-ascii digits are not digits`() {
+        val nonAscii = listOf(
+            "OL\u0661\u0662ap",
+            "OL\u0968\u0968ap",
+            "OL\uff11\uff12ap",
+            "OL\u06f1\u06f2ap",
+            "IO91vl\u0663\u0669"
+        )
+        for (grid in nonAscii) {
+            assertTrue(
+                "must be refused: " + grid,
+                GridEntry.check(grid) is GridEntry.Verdict.Unusable
+            )
+        }
+    }
+
     /** Nothing typed means the QRZ lookup should run, which is a different outcome from bad input. */
     @Test
     fun `an empty entry is neither acceptable nor unusable`() {
@@ -87,10 +130,14 @@ class GridEntryTest {
         assertEquals(GridEntry.Verdict.Empty, GridEntry.check("   "))
     }
 
-    /** Maidenhead has no odd lengths and no two-character form in this context. */
+    /**
+     * ADIF 3.1.7 permits 2, 4, 6 and 8 characters and nothing between them. A 10 or 12 character
+     * locator stores its first 8 here with the rest in GRIDSQUARE_EXT, which nothing in this app
+     * carries - the field clips at 8, which produces the spec-correct value.
+     */
     @Test
-    fun `only 4 6 or 8 characters can be a grid`() {
-        for (bad in listOf("OL", "OL7", "OL72A", "OL72APX", "OL72AP123")) {
+    fun `only 2 4 6 or 8 characters can be a grid`() {
+        for (bad in listOf("O", "OL7", "OL72A", "OL72APX", "OL72AP123")) {
             val verdict = GridEntry.check(bad)
             assertEquals(
                 "$bad must be refused for length, got $verdict",
diff --git a/core/presentation/src/main/res/values-zh/strings.xml b/core/presentation/src/main/res/values-zh/strings.xml
index 5d313408..d508969f 100644
--- a/core/presentation/src/main/res/values-zh/strings.xml
+++ b/core/presentation/src/main/res/values-zh/strings.xml
@@ -280,6 +280,7 @@
     <string name="wavelog_grid_help">对方报给你的网格。留空则从 QRZ 查询。</string>
     <string name="wavelog_grid_bad">不是有效网格</string>
     <string name="wavelog_grid_square_only">仅方格 - 精度约 100 公里</string>
+    <string name="wavelog_grid_field_only">仅大方格 - 精度约 1000 公里</string>
     <string name="wavelog_mode_hint">模式</string>
     <string name="wavelog_mode_edit">修改模式</string>
     <string name="wavelog_time_hint">时间</string>
diff --git a/core/presentation/src/main/res/values/strings.xml b/core/presentation/src/main/res/values/strings.xml
index 7272880f..85b48983 100644
--- a/core/presentation/src/main/res/values/strings.xml
+++ b/core/presentation/src/main/res/values/strings.xml
@@ -311,6 +311,7 @@
     <string name="wavelog_grid_help">What they sent you. Left empty, it is looked up on QRZ.</string>
     <string name="wavelog_grid_bad">Not a grid square</string>
     <string name="wavelog_grid_square_only">Square only - accurate to about 100 km</string>
+    <string name="wavelog_grid_field_only">Field only - accurate to about 1000 km</string>
     <string name="wavelog_mode_hint">Mode</string>
     <string name="wavelog_mode_edit">Edit the mode</string>
     <string name="wavelog_time_hint">Time</string>
diff --git a/feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/LogTab.kt b/feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/LogTab.kt
index 1173aeb4..c8033f4b 100644
--- a/feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/LogTab.kt
+++ b/feature/radar/src/main/java/com/rtbishop/look4sat/feature/radar/LogTab.kt
@@ -473,12 +473,13 @@ private fun ExpandedLogInput(
                     // where a wrong square is worse than a missing one.
                     text = when (gridVerdict) {
                         is GridEntry.Verdict.Unusable -> stringResource(id = R.string.wavelog_grid_bad)
-                        is GridEntry.Verdict.Acceptable ->
-                            if (gridVerdict.warning == GridEntry.Warning.SQUARE_ONLY) {
+                        is GridEntry.Verdict.Acceptable -> when (gridVerdict.warning) {
+                            GridEntry.Warning.FIELD_ONLY ->
+                                stringResource(id = R.string.wavelog_grid_field_only)
+                            GridEntry.Warning.SQUARE_ONLY ->
                                 stringResource(id = R.string.wavelog_grid_square_only)
-                            } else {
-                                stringResource(id = R.string.wavelog_grid_help)
-                            }
+                            null -> stringResource(id = R.string.wavelog_grid_help)
+                        }
                         GridEntry.Verdict.Empty -> stringResource(id = R.string.wavelog_grid_help)
                     },
                     style = MaterialTheme.typography.bodySmall