Limitations and considerations
The first thing you need to understand is that there is a limit to the number of validation rules that can be active at the same time for a given object.
As of the summer 2020 release, depending on your edition, you can have the following number of active validation rules per object:
500: Unlimited and Performance Edition
100: Enterprise and Developer Edition
20: all other editions
Further reading
To have a look at major limits and allocations related to Salesforce editions, refer to Salesforce Help at https://help.salesforce.com/articleView?id=overview_limits_general.htm&type=5.
If you want to know the limits specific to your organization, go to Setup | Object Manager, select a Salesforce object, and then click on the Object Limits side tab:
Figure 4.8 – Object Limits page
There is another feature specific to validation rules, that is, the VLOOKUP function.
The VLOOKUP function
The VLOOKUP...
