diff --git a/nufxlib-0/Archive.c b/nufxlib-0/Archive.c
index b2c9104..c287e31 100644
--- a/nufxlib-0/Archive.c
+++ b/nufxlib-0/Archive.c
@@ -308,6 +308,8 @@ Nu_UpdateWrapper(NuArchive* pArchive, FILE* fp)
         BailError(err);
         Nu_WriteFour(pArchive, fp, archiveLen512);
 
+        /* probably ought to update "modified when" date/time field */
+
         /* seek just past end of BNY wrapper */
         err = Nu_FSeek(fp, kNuBinary2BlockSize - (kNuBNYDiskSpace+4), SEEK_CUR);
         BailError(err);
@@ -459,6 +461,10 @@ bail:
  * That way, if the application is trying a series of libraries to find
  * one that will accept the file, we don't generate spurious complaints.
  *
+ * Since there's a fair possibility that whoever is opening this file is
+ * also interested in related formats, we try to return a meaningful error
+ * code for stuff we recognize (especially Binary II).
+ *
  * On exit, the stream will be positioned just past the master header.
  */
 static NuError
@@ -491,7 +497,7 @@ Nu_ReadMasterHeader(NuArchive* pArchive)
             err = kNuErrNotNuFX;
             /* probably too short to be BNY, so go ahead and whine */
             Nu_ReportError(NU_BLOB, kNuErrNone,
-                "Might be Binary II, but it's not NuFX");
+                "Looks like a truncated Binary II archive?");
             goto bail;
         }
 
@@ -502,7 +508,7 @@ Nu_ReadMasterHeader(NuArchive* pArchive)
          */
         count = Nu_ReadOne(pArchive, fp);
         if (count != 0) {
-            err = kNuErrNotNuFX;
+            err = kNuErrIsBinary2;
             /*Nu_ReportError(NU_BLOB, kNuErrNone,
                 "This is a Binary II archive with %d files in it", count+1);*/
             DBUG(("This is a Binary II archive with %d files in it\n",count+1));
@@ -537,6 +543,7 @@ Nu_ReadMasterHeader(NuArchive* pArchive)
         err = kNuErrNotNuFX;
 
         if (isBinary2) {
+            err = kNuErrIsBinary2;
             /*Nu_ReportError(NU_BLOB, kNuErrNone,
                 "Looks like Binary II, not NuFX");*/
             DBUG(("Looks like Binary II, not NuFX\n"));
diff --git a/nufxlib-0/MiscUtils.c b/nufxlib-0/MiscUtils.c
index f2ffbda..9af5aad 100644
--- a/nufxlib-0/MiscUtils.c
+++ b/nufxlib-0/MiscUtils.c
@@ -174,6 +174,9 @@ Nu_StrError(NuError err)
     case kNuErrDamaged:
         return "Original archive may have been damaged";
 
+    case kNuErrIsBinary2:
+        return "This is a Binary II archive";
+
     default:
         sprintf(defaultMsg, "(error=%d)", err);
         return defaultMsg;
diff --git a/nufxlib-0/NufxLib.h b/nufxlib-0/NufxLib.h
index 5d3f4c2..e4b19dd 100644
--- a/nufxlib-0/NufxLib.h
+++ b/nufxlib-0/NufxLib.h
@@ -101,7 +101,9 @@ typedef enum NuError {
     kNuErrLeadingFssep  = -80,      /* names in archives must not start w/sep */
     kNuErrNotNewer      = -81,      /* item same age or older than existing */
     kNuErrDuplicateNotFound = -82,  /* "must overwrite" was set, but item DNE */
-    kNuErrDamaged       = -83       /* original archive may have been damaged */
+    kNuErrDamaged       = -83,      /* original archive may have been damaged */
+
+    kNuErrIsBinary2     = -90,      /* this looks like a Binary II archive */
 } NuError;
 
 /*
@@ -333,14 +335,14 @@ typedef union NuDataSink NuDataSink;        /* dummy def for internal struct */
  * NuFX Date/Time structure; same as TimeRec from IIgs "misctool.h".
  */
 typedef struct NuDateTime {
-    unsigned char   second;
-    unsigned char   minute;
-    unsigned char   hour;
-    unsigned char   year;
-    unsigned char   day;
-    unsigned char   month;
-    unsigned char   extra;
-    unsigned char   weekDay;
+    unsigned char   second;         /* 0-59 */
+    unsigned char   minute;         /* 0-59 */
+    unsigned char   hour;           /* 0-23 */
+    unsigned char   year;           /* year - 1900 */
+    unsigned char   day;            /* 0-30 */
+    unsigned char   month;          /* 0-11 */
+    unsigned char   extra;          /* (must be zero) */
+    unsigned char   weekDay;        /* 1-7 (1=sunday) */
 } NuDateTime;
 
 /*
@@ -499,7 +501,7 @@ typedef struct NuSelectionProposal {
 } NuSelectionProposal;
 
 /*
- * Passed into the OuputPathnameFilter callback.
+ * Passed into the OutputPathnameFilter callback.
  */
 typedef struct NuPathnameProposal {
     const char*         pathname;