Impact of wrong parameter names in a campaign url

In the evaluation process of Piwik, we came across a query like:

How piwik will behave if we have supplied a wrong parameter name in an url for our campaign tracking? Will piwik accept traffic from such url and if yes in which category piwik will place this traffic?

Can you please elaborate on this? What do you mean by supplying wrong parameter?
Piwik will always accept traffic, If it won’t be able to recognize the visit as coming from campaign it will put it in Direct traffic category.