code: func (f *defaultFormats) DelByName(name string) bool {
  	f.Lock()
  	defer f.Unlock()
  
  	nme := f.normalizeName(name)
  
  	for i, v := range f.data {
  		if v.Name == nme {
  			f.data[i] = knownFormat{} // release
  			f.data = append(f.data[:i], f.data[i+1:]...)
  			return true
  		}
  	}
  	return false
  }
docs: // DelByName removes the format by the specified name, returns true when an item was actually removed