Parameters is the way how to add dynamic interpretation to static objects (queries, graph, reports).
In contrast to macros are the objects changed interactively by user.

Params are defined in query part of objects. Every parameter name starts with @.

In the (query) parameters dialog you can add custom caption and set the parameter type.

According to parameter type will be by running a combobox or normal editor rendered.

If you execute the query you get a warning. It's normal myTracker detected only the first 10 before * and it is not common but valid. Sounds and it were realy simple to use it. Now you don't have to define for every issue type a separated query. And it is possible for example for reports define a start and end datum. Or whatever You need.

We can sligtly modify the select as select first @X * from issue where issuetype = @issuetype order by id desc. Now myTracker will also ask for number of issues. So we could name this query as Last X. This example would probably nobody use, but it shows the power of simplicity.