Have been discussing this with a few friends of mine. Is the order of co-first authors important in a manuscript? I was told that, if the list of author order is AAA*, BBB*, CCC,DDD,EEE, with * denotes equal contribution, regardless of co-authorship or not, AAA is still the Main leader of this project? My question is, if that is the case, what is the point of having a co-first annotation ?

Dear, For any technical writing it is necessary that the sequence of ordering must be specified as all the correspondence needs to be done with first author only. Moreover in general their is some thing called "Academic Performance Index (API)" in case your are a first author then you get 100% credit for the same for your writing, in case you are second author then you get 20% less credit and subsequent authors get their share.

Hope that this helps. In case you need any more suggesting do let me know.

Its difficult and topic in a lot of discussions lately. The problem is, with the general citation mechanism in place (XXX et al) people keep fighting over the first position, even if they are equally contributing. I have also heard that people start to mess with the order of authors in their CV to reflect their own contribution better.

In an ideal world, both would be cited as main authors - but this change hasn't arrived yet. Although I am sure it will be standard within a few years because more and more researchers work interdisciplinary and share the main workload with someone from another field.

For the time being, if possible I personally would try to keep things as equal as possible and switch the position of both co-authors every other paper. Its not absolutely fair but the best one can do at the moment I guess.

Unfortunately the first name gets remembered, even if the other names contributed equally. Helps if your surname begins with an 'A'!