What do the symbols in the references of the paper mean?

What does the paper reference mean?

Note: The English document identification code should correspond to the Chinese. [Reference type identification code] M Monograph; C - Collection; N Newspaper article News; J Journal article; D Dissertation Degree; R Report Report; S Standard; P Patent Patent; [M]; Journal[J]; Proceedings[c]; Dissertation[D]; Standard[S]; Report[R]; Patent[P]; Newspaper[N]; (2) Electronic document type identification: database [DB]; computer program [CP]; electronic bulletin [EB]; (3) Electronic document carrier type and identification: online database [DB/OL];

National journal publishing format requirements are in The literature identification code should be marked below the CLC classification number, and the regulations are as follows: The author can choose an identification code from the following A, B, C, D, and E to reveal the nature of the article: A Theoretical and applied research academic papers (including Review report); B practical results report (science and technology), summary of theoretical learning and social practice (technology); C articles on business guidance and technical management (including special comments); D general communications, reports, interviews, etc.; E files , information, characters, books and periodicals, knowledge introduction, etc. Note: The English document identification code should correspond to the Chinese. [Reference type identification code] M Monograph; C - Collection; N Newspaper article; J Journal article; D Dissertation Degree; R Report; S Standard; P Patent; A Extracted literature from monographs and collections of papers; Z Other unexplained documents (1) Document type identification: monograph [M]; journal [J]; thesis Collection [c]; thesis [D]; standard [S]; report [R]; patent [P]; newspaper [N]; (2) Electronic document type identification: database [DB]; computer program [CP]; Electronic Bulletin [EB]; (3) Electronic document carrier type and identification: Online Database [DB/OL];