Hello Helmut,
There are 2 ways to create new fields in CRM Web UI:
1. Application Extension Tool (AET)
2. Custom Development
The following link explain the advantages and disadvantages of each one:
How to create new fields: AET Vs Custom Development - CRM - SCN Wiki
In summary, AET is UI-driven and require no technical/development background.
I would recommend to use AET for most of cases. On the other hand, if you need to add some logic flow or control the field behaviour, you may need to perform some custom development.
When using AET, you have the option to define the search relevance for the new created fiel. So, this will allow you to make the field available for search and result list:
I have always used the context node CUSTOMER_H/BTCUSTOMERH to create the new fields and always worked.
For a detailed step-by-step, see the following link:
Step by step to create new fields on UI via Application Extension Tool - CRM - SCN Wiki
Last but not least, there is no specific documentation for CRM Web UI in ITSM or ChaRM. Once this is part of CRM functionality and SolMan is only using it, you may need to search for CRM documentation.
Anyway, there is a very helpful wiki about CRM Web UI and I recommend you to take a look at that:
CRM Web Client UI Framework - CRM - SCN Wiki
I hope it helps.
Cheers,
Fernando