Sage Advice Returns! [Official Thread]

The issue is threefold:

1. The SAG quote claims there is no special game meaning for the term line of sight. There is, so that's incorrect. 

2. If there is a distinction between the rule and the plain English reading of the phrase, then the text doesn't distinguish clearly enough which it is using. 

3. At least some of the definitions of "line of sight" don't actually reference being able to see the target. In short, if you check those definitions, you'd still conclude that being invisible is irrelevant to the application of the rules. Here's Websters, which I gather most Americans would probably turn to, and note that it refers only to lines between two points, not that you can see one from the other:

line of sight
noun phrase
1: a line from an observer's eye to a distant point
2: the line between two points
specifically : the straight path between a transmitting antenna (as for radio or television signals) and a receiving antenna when unobstructed by the horizon

Why is that answer in the SAC not answering the question?

"If you can’t see something, it’s not within your line of sight" <- That's the ruling to consider.

EDIT: for clarity.

Feel free to quote where someone said that it didn't answer the question, then we can actually discuss the claim.

Quote from Linklite >>

Feel free to quote where someone said that it didn't answer the question, then we can actually discuss the claim.

 Question. Doubt. A post questioning the SAC:

Quote from Anarion66 >>

 [...] So, a line of sight can exist even if you can't see along it, for example you have the Blinded condition (i.e., you have actually been blinded by some attack or effect).

Both the SAC entry and possibly the PHB Glossary entry for Frightened should be corrected.

 
 What I'm saying is that the SAC resolves that line in blue: "If you can’t see something, it’s not within your line of sight" 

Line of Sight has a special meaning in the rules in DMG. Either the person that wrote this SAC didn't know this.

Or infer that line of sight and Line of Sight is different.