Added FAQ

FAQ.md

@@ -267,6 +267,7 @@ Fonts, sizes, colors, etc should be material design whenever possible.
 * [(147) What should I know about third party versions?](#user-content-faq147)
 * [(148) How can I use an Apple iCloud account?](#user-content-faq148)
 * [(149) How does the unread message count widget work?](#user-content-faq149)
+* [(150) Can you add cancelling calendar invites?](#user-content-faq150)
 
 [I have another question.](#user-content-support)
 
@@ -2864,6 +2865,20 @@ Tapping on the notification will synchronize all folders for which synchronizati
 
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+<a name="faq150"></a>
+**(150) Can you add cancelling calendar invites?**
+
+Cancelling calendar invites (removing calendar events) requires write calendar permission,
+which will result in effectively granting permission to read and write *all* calendar events of *all* calendars.
+
+Given the goal of FairEmail, privacy and security, and given that it is easy to remove a calendar event manually,
+it is not a good idea to request this permission for just this reason.
+
+Inserting new calendar events can be done without permissions with special [intents](https://developer.android.com/guide/topics/providers/calendar-provider.html#intents).
+Unfortunately, there exists no intent to delete existing calendar events.
+
+<br />
+
 ## Support
 
 Only the latest Play store version and latest GitHub release are supported.