diff --git a/schemas/LitCal.json b/schemas/LitCal.json
index 9d4e48d0..c9940de2 100644
--- a/schemas/LitCal.json
+++ b/schemas/LitCal.json
@@ -204,9 +204,10 @@
                     "StsBasilGreg"
                 ]
             },
-            "litcal": {
-                "Advent1_vigil": {
+            "litcal": [
+                {
                     "event_idx": 1076,
+                    "event_key": "Advent1_vigil",
                     "name": "Dominica Prima Adventus Missa in Vigilia",
                     "date": 1701475200,
                     "color": [
@@ -218,6 +219,7 @@
                     "type": "mobile",
                     "grade": 7,
                     "grade_lcl": "celebratio altioris ordinis quam sollemnitatis",
+                    "grade_abbr": "S✝",
                     "grade_display": "",
                     "common": [],
                     "common_lcl": "",
@@ -235,8 +237,9 @@
                     "liturgical_season": "ADVENT",
                     "liturgical_season_lcl": "Tempus Adventus"
                 },
-                "Advent1": {
+                {
                     "event_idx": 583,
+                    "event_key": "Advent1",
                     "name": "Dominica Prima Adventus",
                     "date": 1701561600,
                     "color": [
@@ -248,6 +251,7 @@
                     "type": "mobile",
                     "grade": 7,
                     "grade_lcl": "celebratio altioris ordinis quam sollemnitatis",
+                    "grade_abbr": "S✝",
                     "grade_display": "",
                     "common": [],
                     "common_lcl": "",
@@ -267,7 +271,7 @@
                     "liturgical_season": "ADVENT",
                     "liturgical_season_lcl": "Tempus Adventus"
                 }
-            },
+            ],
             "messages": [
                 "The Solemnity 'Sancti Ioseph Sponsi Beatæ Mariæ Virginis' falls on Dominica IV in Quadragesima in the year 2023, the celebration has been transferred to the following Monday (20 Martius) as per the <a href=\"http://www.cultodivino.va/content/cultodivino/it/rivista-notitiae/indici-annate/1990/284-285.html\">Decree of the Congregation for Divine Worship</a>.",
                 "'Dominica XVIII «Per Annum»' is superseded by the FESTUM DOMINI 'In Transfiguratione Domini' in the year 2023."
@@ -334,6 +338,9 @@
                 "grade_lcl": {
                     "type": "string"
                 },
+                "grade_abbr": {
+                    "type": "string"
+                },
                 "grade_display": {
                     "type": "string"
                 },
@@ -412,6 +419,8 @@
                 "color_lcl",
                 "type",
                 "grade",
+                "grade_lcl",
+                "grade_abbr",
                 "grade_display",
                 "common",
                 "common_lcl",
@@ -465,6 +474,9 @@
                 "grade_lcl": {
                     "type": "string"
                 },
+                "grade_abbr": {
+                    "type": "string"
+                },
                 "grade_display": {
                     "type": "string"
                 },
@@ -546,6 +558,8 @@
                 "color_lcl",
                 "type",
                 "grade",
+                "grade_lcl",
+                "grade_abbr",
                 "grade_display",
                 "common",
                 "common_lcl",
diff --git a/schemas/openapi.json b/schemas/openapi.json
index 61001508..b86c20d2 100644
--- a/schemas/openapi.json
+++ b/schemas/openapi.json
@@ -4788,6 +4788,15 @@
                       "SOLEMNITY"
                     ]
                   },
+                  "GradeAbbr": {
+                    "description": "The logical importance of the celebration, represented in abbreviated human readable form and localized according to the current requested locale",
+                    "type": "string",
+                    "examples": [
+                      "w",
+                      "F",
+                      "S"
+                    ]
+                  },
                   "DisplayGrade": {
                     "type": "string",
                     "description": "will often be empty, in which case the ***grade*** or ***gradeLcl*** properties can be used, for the purpose of displaying the rank of the current liturgical event. If non empty, will contain the localized rank of the liturgical event and should be used instead of the ***grade*** or ***gradeLcl*** properties for display purposes"
diff --git a/src/Enum/LitGrade.php b/src/Enum/LitGrade.php
index 2dd616df..f45116e4 100644
--- a/src/Enum/LitGrade.php
+++ b/src/Enum/LitGrade.php
@@ -196,7 +196,7 @@ public function i18n(int $value, bool $html = true, bool $abbreviate = false): s
                 /**translators: liturgical rank. Keep lowercase  */
                 $grade = $this->locale === LitLocale::LATIN ? 'celebratio altioris ordinis quam sollemnitatis' : _("celebration with precedence over solemnities");
                 /**translators: liturgical rank 'HIGHER SOLEMNITY' in abbreviated form */
-                $gradeAbbr = $this->locale === LitLocale::LATIN ? 'S+'                : _("S+");
+                $gradeAbbr = $this->locale === LitLocale::LATIN ? 'S✝'                : _("S✝");
                 $tags = ['<B><I>','</I></B>'];
                 break;
             default: