Author: Pablo Reyes 

In Delphi 5 the object inspector allow us to view properties and events by 
categories. We can instruct Delphi which category the properties and events of our 
components belongs to and even to create our own categories. 

Answer:

1. To instruct Delphi which category a property belongs to: 
We have to do that in the Register procedure. The function 
RegisterPropertyInCategory has four overloaded versions. This is one of them. In 
this version we instruct Delphi to assign the property "Version" of our component 
"TMyButton" to the "TMiscellaneousCategory" standard category. 

1   procedure register;
2   begin
3     RegisterComponents('Samples', [TMyButton]);
4     RegisterPropertyInCategory(TMiscellaneousCategory, TMyButton, 'Version');
5   end;


Search Delphi help for more information about other overloaded versions of this 
function. 

2.To create our own category: 
We have to create a new class and derive it from TPropertyCategory or one of the 
existing categories (for example TMiscellaneousCategory). Then, we need to override 
the Name class function. The result value is the name shown by the object 
inspector. 

6   interface
7   
8   TMyCategory = class(TPropertyCategory)
9   public
10    class function Name: string; override;
11  end;
12  
13  implementation
14  
15  class function TMyCategory.Name: string;
16  begin
17    Result := 'My Category';
18  end;
19  
20  then we could use our new category. 
21  
22  procedure register;
23  begin
24    RegisterComponents('Samples', [TMyButton]);
25    RegisterPropertyInCategory(TMyCategory, TMyButton, 'Version');
26  end;


You can also use RegisterPropertiesInCategory to register more than one property with one category at a time.