SAP HR T-Codes, Create new infotype in SAP HR

Any Idea about Tcode OOOS

I want to try transaction OOOS .  How actually does it works?

I have a entry  like this

PA20  PD10  S     RHRHAZ00    PA-REPORT-START_SKIP

What is PD10 where I can find this request code.

I'm not sure what you're asking but if you want the user menu path that will give you the same report:

HR -> OM -> Tools -> Database -> RE_RHRHAZ00 - Display DB records

and

Check out OSS note 87867 for some info related to OOOS.

Display all InfoTypes and their respective description

Is there a transaction that I can run to display all InfoTypes and their respective description?

You can run transaction PPCI and press F4 in the infotype field.

Create New InfoTypes

Why do we need to create new infotypes other than the existing SAP standard infotypes when SAP has already created so many, and what kind of enhancements are needed and for what reason.

We do need to create new infotypes if the client's requirement doesn't get fulfilled by SAP-standard infotypes. That's why they are termed as customer-specific infotypes. As per the enhancement goes, one can add new fields in the infotype, activate/deactivate certain fields,  as per the requirement.

To create new infoytpes:

Start transaction PM01

- You access the Create Info type screen:

- In the Info type no. Field, enter the four-digit number of the info type you want to create. When you specify the info type number, please remember to enter any leading zeros.

- In the Sub-Objects group box, flag CI Include.

- Choose Create. The Dictionary: Initial Screen is displayed.

- Create the Cl include.

- Choose Activate.

- Return to the Create Info type screen.

- Choose Create All.