Normalization Data Services is also referred to as Canonicalization Service Client during the activation of the given plugin.You would encountered the term 'Canonicalization Service Client' during Normalization Data Services activation via the error "The active plugin Field Normalization will conflict with Canonicalization Service Client"
This error is displayed to ensure that the customers do not try to normalize the same field on a table both via Field Normalization plugin and via Normalization Data Services plugin. If there exists any combination of the same company name in both field normalization and normalized company name in normalization data services the following can happen:
a. Overlapping normalization where the normalized company name in normalization data services will get normalized again by field normalization.
b. Duplication of core company records where there is the same name.
The best practice specific to both issues is to not have overlapping company names in both field normalization and normalization data services.