this was an idea discussed few years back on the forum.
this is already possible. there are few points to note here.
the code should be <a href= and not<a href:
as per your example, the code should be inserted for each inventory item edit page and not in the custom field creation form itself. you may insert it as a Form Default but you should not enter it as a description for the custom field like you have done.
the links will open in Manager itself if you point it to any webpage because Manager itself is a browser. you just have to make sure you add a weblink as http://www.xyz.com or https://www.xyz.com and not simply www.xyz.com (personal experience).
not adding http or https to the weblink will simply redirect to your business selection page in Manager.
my responses are based on Manager desktop version 20.2.6 running on Windows 10.
CAUTION: although Manager functions like a browser and is capable of navigating to any page on the internet, it does not have any in-built security features like other web browsers. Therefore, it is the responsibility of the user to make sure you do not navigate to any malicious weblink which can harm your system or most importantly your business database file.
I like it how it is now, because if I do not want it to be the “value” – in which case the link would not appear during entry, it would appear as a resource during view; instead, I want it to be something more like help for the user doing the creation.
Noted, but I am not expecting any anti-virus features from Manager.io, in fact I like the fact that there isn’t any bloatware here.