1. The first author is the signature of the paper, and the second and third authors are the second and third authors. Generally speaking, it depends on the weight of your article. If the weight is enough, you can publish multiple authors. An article in a foreign multi-center clinical trial can reach 100 people.

2. Articles generally have correspondents, and correspondents refer to the owners and directors of articles. Someone else has a correspondent, which means contact.

This can also be determined by both parties through consultation. If there is no agreement, usually the first author ranks first, the second author ranks second, and so on.

Extended data

There is generally no limit to the number of authors who publish papers, but usually no more than six.

Generally speaking, the first author ranks first, the second author ranks second and the third author ranks third, so 1 is generally written.

But you can use the method of annotation, that is, add a comment after the author's name, and then explain that there are often no more than two people in common with the second author and the third author; But this kind of situation is rare, and general publishers and conference organizers are not allowed to do so.

Intermediate titles require the first author, and many titles are evaluated by requiring the articles published by contestants to be independent or the first author, second author or even third author, and the evaluation effect is very poor.

Reference: the first author of Baidu Encyclopedia