minecraft-bedrock-json-schemas/source/general/block/identifier.json

{
  "$id": "blockception.minecraft.block.identifier",
  "description": "A minecraft block identifier.",
  "examples": ["namespace:block"],
  "pattern": "^[0-9a-zA-Z:_\\.\\-]+$",
  "title": "Block Identifier",
  "type": "string",
  "defaultSnippets": [{ "label": "New Identifier", "body": "$1:$2" }]
}