When to use CGCZ (Match up master data)?

Hi there

I am fairly new in EHS & I have to admit I am utterly confused about the purpose of transaction CGCZ. I came across it everywhere (IMG, SAP help, config guides...), but the more I am reading about it, the more confused I get. Maybe someone could help me out?

• What is the purpose of the different options in CGCZ?
• When should I run CGCZ? I could imagine I need to run it after having a new value assignment type created (as an example)?
• When must I not run CGCZ? The default option is "Activate Phrasing of characteristics". Naive as I am, I ran it with this option. Which then messed up all our characteristics, as we don't even use phrases... I also saw a screenshot of a previous release and apparently CGCZ used to have a function to disable phrasing in characteristics. But not anymore...
• Do I have to execute it in DEV, QAS & PROD? I've noticed that option "Generate symbols" creates table entries, which however don't get added to a transport. I suppose then, I need to run it in each system?
• Is it harmful to run it several times?

Thanks in advance

Jan