You can share a SharePoint Online site (or a list or document, etc.) with external users, if your global setting for the site collection allows this. Although you need to select a specific permission group for these external users (from the list of available permission groups in that site), those external user do not have the same capabilities as a ‘normal’ user of the site.
The reason for this is that external users do not have an Office 365 license linked to them, at least not unless you choose to assign that to them.
As a result there are a number of things you cannot do as an external user. Microsoft has some documentation on those limitations:
Manage external sharing for your SharePoint Online environment
I recently found that there is at least one other thing that external users cannot do, which is not documented: An external user cannot share something with another external user by inviting them.
On the one hand that makes sense, because that could potentially allow an endless string of external users in the site. On the other hand it is strange: if I am allowed into the site as an important user with broad permissions, then why can’t I share anything with another (new) external user?
What I haven’t tried yet is to see if an external user can share with new external users once an Office 365 / SharePoint Online license is assigned to his account. Will update this post if I find out.
While I was developing a workflow to be triggered on a changed Document Library item in SharePoint Online (this was a Word document), I noticed something interesting about the versioning.
In the workflow I was checking if the version number had already increased, thinking that in this way I could determine if the user was done editing.
As it turns out, it depends if you are using Word or Word Online. What happens is this:
If you are using your local MS Word installation, then you are basically working offline. You only connect to SharePoint Online when you take an explicit action like saving or checking-in a document. SharePoint will not create a new version in the version history until you click Save in Word. So even if you type lots of new text and update some properties, but close the document without saving, nothing is changed in the version history.
This is very different in Word Online. As you probably know, there is no Save button in Word Online, because any change is automatically saved for you. So that made me wonder: if I edit a document in Word Online for half an hour, making many changes, then that document is going to be saved automatically dozens of times. So does that create dozens of new versions in the history? Well, that would be awkward and luckily the answer is no.
What happens is that Word Online creates a new version in the version history (in SharePoint Online) when the first change is being saved in Word Online. So as long as you don’t touch anything in Word Online and just read the document, you get no new version. Then, on every next change in the document that is saved in Word Online, that same new version is *updated*. You can see the Modified time change in the version history.
That is actually the same behavior that we are used to in (local) Word: as long as you do not close the document, subsequent saves will be considered as an update to the same version. This is true if you use both minor and major versions, but also if you only use major versions.
So coming back to my workflow, the downside here is that a new version in the history does not always mean that the user explicitly saved his work. That depends if Word Online or (local) Word was used. Your new version will in any case appear in your version history more quickly when using Word Online.