What are the rules for capitalization of abbreviations in English?

Capitalization rules of English letters 1 The first letter at the beginning of a sentence should be capitalized. "I (I)" should be capitalized anywhere in the sentence. What's her name? Mary and I are teachers. 2. The initials of proper nouns such as place names, country names and names should be capitalized. For example: Russia, Youyang, Chengdu and Jack. 3. Some kinship (such as mother, sister, mother, father, etc. ) should be capitalized when used as a salutation. Thank you, grandma. Thank you, grandma. 4. Capitalize the title or the first letter of the title before the person's name. For example: Mr. Smith, Dr. Wang, Miss Mary. The first letter of a noun or adjective indicating a language or nationality should be capitalized. For example: Russians, Russians, China, China. 6. In direct speech, the first letter of a sentence should be capitalized. For example, "Well," I said, "you made a mistake. The letter is not in the apartment." "Well," I said, "you must be mistaken. This letter is not in that house. " 7. The first letter of the week and month names should be capitalized, but the first letter of the season is not capitalized. For example: Sunday, Sunday, August, winter, spring. 8. The first letter of the first notional word in the names of some large festivals should be capitalized. For example, Children's Day, National Day and Teacher's Day. 9. Proper noun phrases composed of common nouns, except articles, short prepositions and conjunctions, should capitalize the first letter of each word. For example, the Great Wall of America. 10. Capitalize the first letter of each notional word (function words: adverbs, prepositions, conjunctions, auxiliary words, exclamations and onomatopoeias) in the names of large conferences, documents and treaties. The title of the book and the name of the newspaper should be capitalized, and the first letter of each entity word in the title of the article should be capitalized. Such as: China Daily, China Daily, new york Times and new york Times, their classes, their classes (article titles), Warsaw Pact, and taking English tutoring papers as examples. 1 1. The first letter of the first word in each line should be capitalized. 12. Capitalize the first letter of a word indicating an address or position. Example: Mr. Green, Dr. Li Li 13. Most abbreviations should be capitalized. For example: CCTV (China Central Television), ID (Identity Card), CD (Disc) 14. "I" and "OK" should be capitalized anywhere in the sentence. Tom and I are students. Tom and I are students. It doesn't matter. You're welcome.