diff --git a/man/rem2ps.1.in b/man/rem2ps.1.in
index 01eae2f9..fef18c9b 100644
--- a/man/rem2ps.1.in
+++ b/man/rem2ps.1.in
@@ -516,10 +516,28 @@ MOON, etc.)
 If any TAG clauses are present, the \fBtags\fR key will be present and consist
 of a comma-separated list of tags.
 .TP
-.B info [\fIarray\fR]
+.B info \fR{ \fIhash\fR }
 If any INFO clauses are present, the \fBinfo\fR key will be present.  Its
-value will be an array of info strings, one for each INFO clause and in
-the same order as the INFO clauses.
+value will be a hash of info key-value pairs.  Each key is the header
+from an INFO string, \fIconverted to all upper-case\fR.  The value is the
+valu from the INFO string.
+.RS
+.PP
+For example, the following REM command:
+.PP
+.nf
+        REM INFO "Location: Boardroom" INFO "Summary: None" MSG whatever
+.fi
+.PP
+will produce the following \fBinfo\fR hash:
+.PP
+.nf
+        "info" : {
+            "LOCATION" : "Boardroom",
+            "SUMMARY" : "None"
+        },
+.fi
+.RE
 .TP
 .B time \fIt\fR
 If an AT clause was present, this key will contain the time of the AT clause
diff --git a/man/remind.1.in b/man/remind.1.in
index 6ebba6f3..dd2567e1 100644
--- a/man/remind.1.in
+++ b/man/remind.1.in
@@ -1365,11 +1365,20 @@ to each distinct REM command.
 .PP
 The \fBINFO\fR keyword is similar to \fBTAG\fR but is intended to convey
 metadata about an event, such as its location.  Back-ends will have their
-own rules about the format of the \fIinfo_string\fRs and must ignore
-\fIinfo_string\fRs they don't recognize.  Note that \fBINFO\fR must
+own rules about which \fIinfo_string\fRs they recognize, and must ignore
+\fIinfo_string\fRs they don't recognize. Note that \fBINFO\fR must
 be followed by a quoted string; you can include newlines in the string
 by supplying them as "\\n".
 .PP
+An INFO string \fImust\fR be of the form "Header: Value".  The header
+can consist of any printable character, but cannot contain whitespace.
+The value can consist of any characters you like.  Space may not
+appear before the colon, but can appear afterwards; such space is not
+considered to be part of the value.  If there is more than one INFO
+string for a given reminder, there cannot be any duplicate headers.
+Case is ignored when determining if a header is a duplicate of an
+existing one.
+.PP
 For example, a hypothetical back-end might let you set the location
 and description of a reminder like this:
 .PP
diff --git a/src/calendar.c b/src/calendar.c
index c63c898a..ecbd3518 100644
--- a/src/calendar.c
+++ b/src/calendar.c
@@ -409,6 +409,23 @@ void PrintJSONString(char const *s)
     }
 }
 
+void PrintJSONStringUC(char const *s)
+{
+    while (*s) {
+        switch(*s) {
+        case '\b': printf("\\b"); break;
+        case '\f': printf("\\f"); break;
+        case '\n': printf("\\n"); break;
+        case '\r': printf("\\r"); break;
+        case '\t': printf("\\t"); break;
+        case '"':  printf("\\\""); break;
+        case '\\': printf("\\\\"); break;
+        default: printf("%c", toupper(*s));
+        }
+        s++;
+    }
+}
+
 void PrintJSONKeyPairInt(char const *name, int val)
 {
     printf("\"");
@@ -2354,6 +2371,41 @@ void WriteJSONTimeTrigger(TimeTrig const *tt)
     }
 }
 
+static void
+WriteJSONInfoChain(TrigInfo *ti)
+{
+    printf("\"info\":{");
+    while (ti) {
+        /* Skanky... */
+        char *colon = (char *) strchr(ti->info, ':');
+        char const *value;
+        if (!colon) {
+            /* Should be impossible... */
+            ti = ti->next;
+            continue;
+        }
+        /* Terminate the string at the colon */
+        *colon = 0;
+
+        value = colon+1;
+        while(*value && isspace(*value)) {
+            value++;
+        }
+        printf("\"");
+        PrintJSONStringUC(ti->info);
+        printf("\":\"");
+        PrintJSONString(value);
+        printf("\"");
+
+        /* Restore the value of the colon */
+        *colon = ':';
+        if (ti->next) {
+            printf(",");
+        }
+        ti = ti->next;
+    }
+    printf("},");
+}
 void WriteJSONTrigger(Trigger const *t, int include_tags, int today)
 {
     /* wd is an array of days from 0=monday to 6=sunday.
@@ -2446,18 +2498,7 @@ void WriteJSONTrigger(Trigger const *t, int include_tags, int today)
     }
     if (include_tags) {
         if (t->infos) {
-            TrigInfo *ti = t->infos;
-            printf("\"info\":[");
-            while (ti) {
-                printf("\"");
-                PrintJSONString(ti->info);
-                printf("\"");
-                if (ti->next) {
-                    printf(",");
-                }
-                ti = ti->next;
-            }
-            printf("],");
+            WriteJSONInfoChain(t->infos);
         }
         PrintJSONKeyPairString("tags", DBufValue(&(t->tags)));
     }
@@ -2473,18 +2514,7 @@ static void WriteSimpleEntryProtocol2(CalEntry *e, int today)
     PrintJSONKeyPairString("passthru", e->passthru);
     PrintJSONKeyPairString("tags", DBufValue(&(e->tags)));
     if (e->infos) {
-        TrigInfo *ti = e->infos;
-        printf("\"info\":[");
-        while (ti) {
-            printf("\"");
-            PrintJSONString(ti->info);
-            printf("\"");
-            if (ti->next) {
-                printf(",");
-            }
-            ti = ti->next;
-        }
-        printf("],");
+        WriteJSONInfoChain(e->infos);
     }
     if (e->duration != NO_TIME) {
         PrintJSONKeyPairInt("duration", e->duration);
diff --git a/src/protos.h b/src/protos.h
index d59569f6..bb463179 100644
--- a/src/protos.h
+++ b/src/protos.h
@@ -280,3 +280,5 @@ TrigInfo *NewTrigInfo(char const *i);
 void FreeTrigInfo(TrigInfo *ti);
 void FreeTrigInfoChain(TrigInfo *ti);
 int AppendTrigInfo(Trigger *t, char const *info);
+int TrigInfoHeadersAreTheSame(char const *i1, char const *i2);
+int TrigInfoIsValid(char const *info);
diff --git a/src/trigger.c b/src/trigger.c
index b097331c..4335387e 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -732,8 +732,16 @@ FreeTrigInfoChain(TrigInfo *ti)
 int
 AppendTrigInfo(Trigger *t, char const *info)
 {
-    TrigInfo *ti = NewTrigInfo(info);
-    TrigInfo *last = t->infos;
+    TrigInfo *ti;
+    TrigInfo *last;
+
+    if (!TrigInfoIsValid(info)) {
+        Eprint("%s", tr("Invalid INFO string: Must be of the form \"Header: Value\""));
+        return E_PARSE_ERR;
+    }
+
+    ti = NewTrigInfo(info);
+    last = t->infos;
     if (!ti) {
         return E_NO_MEM;
     }
@@ -741,10 +749,46 @@ AppendTrigInfo(Trigger *t, char const *info)
         t->infos = ti;
         return OK;
     }
+    if (TrigInfoHeadersAreTheSame(info, last->info)) {
+        Eprint("%s", tr("Duplicate INFO headers are not permitted"));
+        FreeTrigInfo(ti);
+        return E_PARSE_ERR;
+    }
     while (last->next) {
         last = last->next;
+        if (TrigInfoHeadersAreTheSame(info, last->info)) {
+            Eprint("%s", tr("Duplicate INFO headers are not permitted"));
+            FreeTrigInfo(ti);
+            return E_PARSE_ERR;
+        }
     }
     last->next = ti;
     return OK;
 }
 
+int
+TrigInfoHeadersAreTheSame(char const *i1, char const *i2)
+{
+    char const *c1 = strchr(i1, ':');
+    char const *c2 = strchr(i2, ':');
+    if (!c1 || !c2) return 1;
+    if (c1 - i1 != c2 - i2) return 0;
+    if (!strncasecmp(i1, i2, (c1 - i1))) return 1;
+    return 0;
+}
+
+int
+TrigInfoIsValid(char const *info)
+{
+    char const *t;
+    char const *s = strchr(info, ':');
+    if (!s) return 0;
+    if (s == info) return 0;
+
+    t = info;
+    while (t < s) {
+        if (isspace(*t) || iscntrl(*t)) return 0;
+        t++;
+    }
+    return 1;
+}
diff --git a/tests/queue1.rem b/tests/queue1.rem
index b4268c98..b746441e 100644
--- a/tests/queue1.rem
+++ b/tests/queue1.rem
@@ -1,6 +1,6 @@
 FSET msgprefix(x) "Priority: " + x + "; Filename: " + filename() + ":  "
 
 REM at 23:56 MSG foo
-REM PRIORITY 42 at 23:57 INFO "A piece of info" MSG bar
-REM PRIORITY 999 at 23:58 INFO "info1" INFO "info2" MSG quux
+REM PRIORITY 42 at 23:57 INFO "Info: yuppers" MSG bar
+REM PRIORITY 999 at 23:58 INFO "Info2: Nope" INFO "Info3: heh" MSG quux
 DO queue2.rem
diff --git a/tests/test-rem b/tests/test-rem
index 530dcb69..902ea8d4 100644
--- a/tests/test-rem
+++ b/tests/test-rem
@@ -650,6 +650,16 @@ EOF
 REM Wed INFO "Location: here" INFO "Summary: Nope" MSG Meeting
 EOF
 
+# Invalid info strings
+../src/remind - 1 Feb 2024 <<'EOF' >> ../tests/test.out 2>&1
+REM Thu INFO "Invalid" MSG wookie
+REM Fri INFO ": foo" MSG blat
+REM Sun INFO "foo bar baz : blork" MSG uua
+
+# Duplicate info string
+REM Sat INFO "Location: here" INFO "location: there" MSG blort
+EOF
+
 # Languages
 for i in ../include/lang/??.rem ; do
     ../src/remind -r -q "-ii=\"$i\"" ../tests/tstlang.rem 1 Feb 2024 13:34 >> ../tests/test.out 2>&1
diff --git a/tests/test.cmp b/tests/test.cmp
index 99c8fbc9..c3fc0704 100644
--- a/tests/test.cmp
+++ b/tests/test.cmp
@@ -23205,12 +23205,12 @@ Enabling test mode: This is meant for the acceptance test.
 Do not use --test in production.
 In test mode, the system time is fixed at 2025-01-06@19:00
 NOTE JSONQUEUE
-[{"priority":2,"eventstart":"2025-01-06T23:59","time":"23:59","nexttime":"23:59","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue2.rem","lineno":1,"type":"MSG_TYPE","body":"XXXX"},{"priority":999,"eventstart":"2025-01-06T23:58","info":["info1","info2"],"time":"23:58","nexttime":"23:58","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":5,"type":"MSG_TYPE","body":"quux"},{"priority":42,"eventstart":"2025-01-06T23:57","info":["A piece of info"],"time":"23:57","nexttime":"23:57","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":4,"type":"MSG_TYPE","body":"bar"},{"priority":5000,"eventstart":"2025-01-06T23:56","time":"23:56","nexttime":"23:56","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":3,"type":"MSG_TYPE","body":"foo"}]
+[{"priority":2,"eventstart":"2025-01-06T23:59","time":"23:59","nexttime":"23:59","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue2.rem","lineno":1,"type":"MSG_TYPE","body":"XXXX"},{"priority":999,"eventstart":"2025-01-06T23:58","info":{"INFO2":"Nope","INFO3":"heh"},"time":"23:58","nexttime":"23:58","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":5,"type":"MSG_TYPE","body":"quux"},{"priority":42,"eventstart":"2025-01-06T23:57","info":{"INFO":"yuppers"},"time":"23:57","nexttime":"23:57","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":4,"type":"MSG_TYPE","body":"bar"},{"priority":5000,"eventstart":"2025-01-06T23:56","time":"23:56","nexttime":"23:56","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":3,"type":"MSG_TYPE","body":"foo"}]
 NOTE ENDJSONQUEUE
 Enabling test mode: This is meant for the acceptance test.
 Do not use --test in production.
 In test mode, the system time is fixed at 2025-01-06@19:00
-{"response":"queue","queue":[{"priority":2,"eventstart":"2025-01-06T23:59","time":"23:59","nexttime":"23:59","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue2.rem","lineno":1,"type":"MSG_TYPE","body":"XXXX"},{"priority":999,"eventstart":"2025-01-06T23:58","info":["info1","info2"],"time":"23:58","nexttime":"23:58","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":5,"type":"MSG_TYPE","body":"quux"},{"priority":42,"eventstart":"2025-01-06T23:57","info":["A piece of info"],"time":"23:57","nexttime":"23:57","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":4,"type":"MSG_TYPE","body":"bar"},{"priority":5000,"eventstart":"2025-01-06T23:56","time":"23:56","nexttime":"23:56","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":3,"type":"MSG_TYPE","body":"foo"}],"command":"QUEUE"}
+{"response":"queue","queue":[{"priority":2,"eventstart":"2025-01-06T23:59","time":"23:59","nexttime":"23:59","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue2.rem","lineno":1,"type":"MSG_TYPE","body":"XXXX"},{"priority":999,"eventstart":"2025-01-06T23:58","info":{"INFO2":"Nope","INFO3":"heh"},"time":"23:58","nexttime":"23:58","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":5,"type":"MSG_TYPE","body":"quux"},{"priority":42,"eventstart":"2025-01-06T23:57","info":{"INFO":"yuppers"},"time":"23:57","nexttime":"23:57","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":4,"type":"MSG_TYPE","body":"bar"},{"priority":5000,"eventstart":"2025-01-06T23:56","time":"23:56","nexttime":"23:56","tdelta":0,"trep":0,"qid":"42424242","rundisabled":0,"ntrig":1,"filename":"../tests/queue1.rem","lineno":3,"type":"MSG_TYPE","body":"foo"}],"command":"QUEUE"}
 BANNER %
 REM 29 MSG One
 -(2): Trig = Thursday, 29 February, 2024
@@ -24503,6 +24503,7 @@ TRANSLATE "Cannot open `%s' for writing: %s" ""
 TRANSLATE "Cannot stat %s - not running as daemon!" ""
 TRANSLATE "Cannot use AT clause in multitrig() function" ""
 TRANSLATE "Do not use ["["]] around expression in SET command" ""
+TRANSLATE "Duplicate INFO headers are not permitted" ""
 TRANSLATE "Error: THROUGH date earlier than start date" ""
 TRANSLATE "Executing `%s' for INCLUDECMD and caching as `%s'" ""
 TRANSLATE "Found cached directory listing for `%s'" ""
@@ -24510,6 +24511,7 @@ TRANSLATE "Function `%s' defined at %s:%d should take %d argument%s, but actuall
 TRANSLATE "Function `%s' redefined (previously defined at %s:%d)" ""
 TRANSLATE "GetValidHebDate: Bad adarbehave value %d" ""
 TRANSLATE "In" ""
+TRANSLATE "Invalid INFO string: Must be of the form \"Header: Value\"" ""
 TRANSLATE "Invalid translation: Both original and translated must have the same printf-style formatting sequences in the same order." ""
 TRANSLATE "Missing REM type; assuming MSG" ""
 TRANSLATE "No Adar A in %d" ""
@@ -24655,11 +24657,16 @@ February 2024 29 4 0
 Sunday Monday Tuesday Wednesday Thursday Friday Saturday
 January 31
 March 31
-{"date":"2024-02-07","filename":"-","lineno":1,"info":["Location: here","Summary: Nope"],"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
-{"date":"2024-02-14","filename":"-","lineno":1,"info":["Location: here","Summary: Nope"],"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
-{"date":"2024-02-21","filename":"-","lineno":1,"info":["Location: here","Summary: Nope"],"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
-{"date":"2024-02-28","filename":"-","lineno":1,"info":["Location: here","Summary: Nope"],"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
+{"date":"2024-02-07","filename":"-","lineno":1,"info":{"LOCATION":"here","SUMMARY":"Nope"},"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
+{"date":"2024-02-14","filename":"-","lineno":1,"info":{"LOCATION":"here","SUMMARY":"Nope"},"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
+{"date":"2024-02-21","filename":"-","lineno":1,"info":{"LOCATION":"here","SUMMARY":"Nope"},"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
+{"date":"2024-02-28","filename":"-","lineno":1,"info":{"LOCATION":"here","SUMMARY":"Nope"},"wd":["Wednesday"],"priority":5000,"body":"Meeting"}
 # rem2ps2 end
+-stdin-(1): Invalid INFO string: Must be of the form "Header: Value"
+-stdin-(2): Invalid INFO string: Must be of the form "Header: Value"
+-stdin-(3): Invalid INFO string: Must be of the form "Header: Value"
+-stdin-(6): Duplicate INFO headers are not permitted
+No reminders.
 Agenda pel dijous, 1 de febrer de 2024:
 
 Language: ca