To subscribe a Google Calendar indirectly shared through group/public

If a calendar is shared to individuals, it will be displayed in My/Other-calendars widgets (in left pane of calendar window) automatically.  However, this is not true when it is shared to public or groups (GoogleApps Contacts, GoogleGroups).

In settings of each calendar (from menu button at the end of each calendar), there is "calendar address" section showing 3 types of links: XML, ICAL, and HTML.  Note that intention of HTML link is to obtain the public URL to view a read-only version of the calendar without signing in to Google Calendar.  It is not to add the calendar into My/Other-calendars list.

Given that we are member of group to which the calendar is shared, here is how to add the calendar into our My/Other-calendars list.

1. Obtain the ICAL link from searching, calendar owner or existing member (e.g., via email or chat).
2. Follow "subscribe" procedure:  At the bottom of the calendar list on the left, click the Add down-arrow button and select Add by URL.  Then input the ICAL link.

Google & Lotus-Notes: calendar-item characteristics & differences

This is situation when an organisation has these 2 email systems running.

	Google Calendar	Lotus-Notes calendar
Showing on calendar	Item is always posted to GCal as '?' mark (looked similar to 'Maybe' response).  We respond 'No' or choose 'Remove' to remove it from GCal.	Item only arrives Inbox and optionally displayed in 'New Notices' pane.  We respond 'accept' or 'add' to get it displayed on calendar.
Colouring	GCal supports multiple calendars and colouring is assigned to each calendar.	LN can only see calendars of others, but neither see altogether simultaneously nor can create multiple calendars in addition to own one.  Colouring is assigned to calendar types (meeting, appointment, anniversary, reminder, to-do)
Participant list	Has option to add guest by any participant.	Has To/CC/BCC classification.
Calendar-item instance between mail & calendar systems	Separate: Deleting the instance in GMail does not effect one in GCal and vice versa.  However, we can respond in either GMail or GCal.	Same: calendar is another view the mail database so that we see same-single instance.  We do not delete it from inbox but manually remove it away (possibly to other folder), or set option (in Tools |Preferences) to remove meeting invitations from inbox after responded.
Item's content	See body of LN-cal item contains .ics attachment (as common as normal Internet email).	See body of GCal item as: "View your event at http://www.google.com/calendar/..."

Also:

• Sender & participants name formatting:  In same system, it can look up its "address book" so that we'll see as full-name written (ex., "John Smith").  Whereas each side will see ones from each other system as Internet-email format (ex., john.smith@company.com).
• Response to GCal invitation via LN can have error such as nonexistent parent document, (field) incorrect data type for operator or @Function.