@@ -149,7 +149,10 @@

   followed by the acquisition number of the spectrum. Also, only the

   \code{pwiz} backend supports extraction of the spectras' IDs from

   \emph{mzML} files. Thus, only \emph{mzML} files read with

-  \code{backend = "pwiz"} provide the spectrum IDs defined in the file.

+  \code{backend = "pwiz"} provide the spectrum IDs defined in the file. 

+  The content of the spectrum identifier depends on the vendor and the 

+  instrument acquisition settings and is reported here as a character, 

+  in its raw form, without further parsing.

 }

 \seealso{