In file https://github.com/mozilla/pdf.js/files/5249872/product1.pdf, the fifth text widget has a default appearance using font F1 and this one is neither in DR nor in AcroForm but in AP::N::Resources.
constructor(parameters) {
    const DEFAULT_ICON_SIZE = 22; 
    super(parameters);
    const dict = parameters.dict;
    this.data.annotationType = AnnotationType.TEXT;
    if (this.data.hasAppearance) {
      this.data.name = "NoIcon";
    } else {
      this.data.rect[1] = this.data.rect[3] - DEFAULT_ICON_SIZE;
      this.data.rect[2] = this.data.rect[0] + DEFAULT_ICON_SIZE;
      this.data.name = dict.has("Name") ? dict.get("Name").name : "Note";
    }
    if (dict.has("State")) {
      this.data.state = dict.get("State") || null;
      this.data.stateModel = dict.get("StateModel") || null;
    } else {
      this.data.state = null;
      this.data.stateModel = null;
    }
  }
}
class LinkAnnotation extends Annotation {