Note: whether the infobox shows "LicenSe" or "LicenCe" is set by |engvar=. Default is en-US ("LicenSe"), alternative is |engvar=en-UK. It should follow the article style, per WP:ENGVAR.
Testcases are at /testcases3

Usage

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| licence_CA =
| licence_EU =
| INN_EMA    = 
| DailyMedID =
| licence_US =
demo
INN: Sildenafil
Clinical data
License data
{{Infobox drug
| drug_name = demo
| INN       = Sildenafil
| licence_CA = Viagra
| licence_EU = yes
| INN_EMA    = Sildenafil
| DailyMedID =
| licence_US = Viagra
}}
demo
INN: Sildenafil
Clinical data
License data
{{Infobox drug
| drug_name = demo
| INN       = Sildenafil
| licence_EU = Viagra
| DailyMedID =
| licence_US = Viagra
}}
demo
INN: Sildenafil
Clinical data
License data
{{Infobox drug
| drug_name = demo
| INN       = Sildenafil
| licence_EU = Viagra
| DailyMedID = Viagra
}}
demo
INN: Sildenafil
Clinical data
License data
{{Infobox drug
| drug_name = demo
| INN       = Sildenafil
| licence_CA = Viagra
| licence_EU = Viagra
| DailyMedID = Viagra
| license_US = Viagra
}}

licence_EU (EMA)

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Drugs that have an EU licence (provided by EMA) should have a link to the EMA site. EMA licences are by INN. The list if EMA licences (INNs) per June 2017 is here (623 INNs). he link is added by setting |licence_EU=yes. The infobox will then show an external link to the EMA licence page (EPAR publications).

In some cases, the INN used by EMA is different from the article's INN. In those cases, use |INN_EMA= to give the name that should be linked to on the EMA site.

As said, EMA licences are given for an INN. When |licence_EU=yes is set, the infobox uses as INN (in this order of priority): |INN_EMA=, |INN=, |drug_name=, <PAGENAME>.

Drugs with the EMA-link are listed in Category:Drug has EMA link‎ (207)