If you’ve ever had the need to build a Skype for Business (or Teams!) dial plan, or sort out the regex for a number range, http://www.ucdialplans.com is your friend.
All around good Canadian kid Ken Lasko has been running this site for years. Got PRIs and need to route 7 digits to the telco vs 10 when it’s a local call? No problem, that’s just a tick box to let the optimizer know that it needs to dip into telco databases and see what exchanges are in your calling area. Internal extensions, trunk codes (9 for an outside line) and more are available.
Working with Cisco or AudioCodes gear? It can do those, too. There’s just so much stuff here, you have to go check it out (and be sure to donate a few bucks so Ken can keep building the awesomeness):
The site is well laid out and easily navigate by scrolling or the menu at the tab. Check it out, I’m sure you’ll find something useful there.