while creating pacakage,in eclipse settings tab add regex field,in regexfield add the following code.
^[0-9a-zA-Z][0-9a-zA-Z-]{1,61}[0-9a-zA-Z]$
tag:validating subdomain in APS package,Validation in APS package.
15)how to identify a package is plesk or PA related
if htdocs folder is there means that package is plesk related package.
but package with htdocs folder will work in PA also