static IndexField getIndexField(byte fieldType) throws UnsupportedFieldException {
		Field indexedField = Field.getField((byte) (fieldType & FIELD_TYPE_MASK));

		byte primaryKeyFeldType = (byte) (fieldType >> INDEX_FIELD_TYPE_SHIFT & FIELD_TYPE_MASK);
		if (primaryKeyFeldType == FIELD_RESERVED_15_TYPE) {
			// 0xf0..0xff - Reserved for Schema use
			throw new UnsupportedFieldException(fieldType);
		}
		if (primaryKeyFeldType == LEGACY_INDEX_LONG_TYPE) {
			return new LegacyIndexField(indexedField);
		}

		Field primaryKeyType = Field.getField(primaryKeyFeldType);
		return new IndexField(indexedField, primaryKeyType);
	}
Get the index field associated with the specified encoded field type.
@param fieldType field type
@return IndexField
@throws UnsupportedFieldException if unsupported fieldType specified
Ghidra/Framework/DB/src/main/java/db/IndexField.java