```javascript
cldr.main("dates/calendars/gregorian/months/format/abbreviated");
```
```
➡ {
  "1": "Jan",
  "2": "Feb",
  "3": "Mar",
  "4": "Apr",
  "5": "May",
  "6": "Jun",
  "7": "Jul",
  "8": "Aug",
  "9": "Sep",
  "10": "Oct",
  "11": "Nov",
  "12": "Dec"
}
```

PS: as Dan Hadman has pointed out, nominative ("stand-alone" from CLDR) and possessive ("format" from CLDR).