Hierarchical numbering patterns?

Anyone with experience setting up hierarchical numbering schemes?
I want to add a column that is hierarchically auto-numbered such that child rows are added to the numbering scheme as increased decimal points. For example
1. Row 1
--1.1 sub item of row 1
---1.1.1 sub item of row 1.1
---1.1.2 sub item of row 1.1
---1.1.3 sub item of row 1.1
--1.2 sub item of row 1
2. Row 2
--2.1 sub item of row 2
---2.1.1 sub item of row 2.1
---2.1.2 sub item of row 2.1
---2.1.3 sub item of row 2.1
--2.2 sub item of row 2
The row number once generated would be static so that if I deleted a row, the other numbered rows continue to exist with their same numbering scheme unless I choose to have them renumbered.
Further, I want to add a prefix to the number scheme based on a selection in a column. For example, if I have a column called "type", I can setup different prefixes of the number pattern based on the selected column value:
ID# Item Type
stry-1 first item Story
-accp-1.1 criteria one Acceptance Criteria
-accp-1.2 criteria two Acceptance Criteria
Answers
There are a few WBS solutions out here in the Community. Let me dig through some notes and see what I can find for you...
HERE is a Published Sheet that I have posted elsewhere in the Community (I can't find the original post).
Let me know if you need any help adapting it to your specific needs.