Mis-filing refers to the improper sorting or placement of documents. Its antonyms include organizing, categorizing, and arranging. Organizing involves placing files in an orderly manner, labeling them correctly, and storing them in a logical sequence for easy retrieval. Categorizing, on the other hand, involves sorting files into specific groups based on their subject matter, author, or date. Arranging refers to organizing files based on their importance, urgency, or priority. All these antonyms aim at preventing mis-filing and ensuring that the documents are easily accessible whenever they are needed. Therefore, to avoid mis-filing, it's crucial to focus on effective organization, categorization, and arrangement of documents.