We suggest that you use your editor to make sure that no line is longer than 80 characters. If blank spaces at the end of a line are meaningful for the formatting program you are using, we suggest that you use special precautions, such as searching with the editor in your machine to determine which lines end up with a blank line and reporting this in the instruction field. For example, MS-DOS insists on having both at the end of a line. If you take the binary pattern of an MS-DOS file and put it into UNIX without any special precautions, it will print with alternating blank lines. This is usually not difficult to correct, but if you are preparing your contribution on an MS-DOS machine we suggest that you pay attention to this problem.
Many mailers modify files or get confused by special characters.
We recommend that you avoid lines of this type. Any decent editor can search for such lines, and if necessary, you can modify them and report this in the instruction field. When files get garbled by mailers, they tend to get garbled in a systematic way, and it is often possible to restore a file into its original state if the sender included some additional information. Generally, changes between different versions of plain TeX have been minor from the point of view of most users. However, old versions of AMSTeX are rather incompatible with newer versions, both in the macros and the styles.