%/$ == $null CAN be the same as !%/$
This all depends on the circumstances, What it seems people are failing to mention is that $null indicates an absense of any state or value for %/$ and will only trigger in that case, where as !%/$ will trigger on any case of %/$ being false/no/0 ect.
At least this is my understanding of the difference.
However to reply more closely to NewScripter's post, just script by the latest version of mIRC, this way your script will be compatible with future versions as scripting formats ect are not changed very often. If/when anything in the scripting language is changed, it is mentioned in the
versions.txt that is included in the mIRC package. So i just suggest reading the
versions.txt any time you upgrade mIRC, this way you will be up to date on any changes that may occur or additions that may improve the scripting language, and you can update yours cripts if/when at all neccersary.
ps. i think you meant to type 6.03 not 6.3