According to Nature's submission guidelines:
To submit a TeX/LaTeX file, please use any of the standard class files such as article.cls, revtex.cls or amsart.cls. All textual material should be provided as a single file in default Computer Modern fonts. Please avoid non-standard fonts and packages and remove all personal macros before submitting.
While it is understandable that any font outside of Computer Modern family is considered as a "non-standard", it is not clear what the non-standard packages are. Is there a definition for the "non-standard package" or a list of packages considered standard?
If Nature hasn't made a clear definition or provided such list, would it be impossible to tell whether package X is OK to use prior to submission? Or is it their way of asking to use as few packages as possible to simplify conversion to Microsoft Word?
myspecialmacros.sty
would certainly count, as would any package that isn't installed in a full TeXLive distribution, namely anything installed in your localtexmf
folder. But it could easily include any package that is in e.g. current TeXLive but is very new and doesn't exist on their (likely older) production system.article.cls
,report.cls
,book.cls
, etc.) because if you have an minimal installation that contains LaTeX, you have those classes as well.article.cls
, don't use a fancier version just because you can". For example, you already have thetabular
environment, so don't use a fancy table formatting package. You already haveenumerate
anditemize
, so don't use theenumitem
package (or whatever) just because it has prettier formatting options.