I have some questions and comments on the subject. Whether or not there is a standard method of notating, I don't know, but people do write them differently.

Let's use as an example an ALS 13579 in r1c2468.

Consider this partial string written two different ways:

1) (6=5)r7c2-(1359=7)r1c2468

2) (6=5)r7c2-(5=1379)r1c2684

As a relative newcomer to notation and a reader trying to figure out what others are doing, my preference is:

(6=5)r7c2-(5139=7)r1c2684

I prefer the multiple numbers to the left of the equal sign so the reader can immediately see that the single digit to the right of the sign is the ending number. We know the starting number is 5 based on the previous term, but the 5139 is out of sequence just to quickly show that the 5 is the end of the previous term and the beginning of the next. This, however, is not critical since even if it's written sequentially as 1359 we know it has to start with 5.

Note that the cells of the ALS are not the sequential r1c2468, but the non-sequential r1c2684. This is so the ending number of the ALS is located in the last cell in the string, i.e., r1c4. It's a little harder to figure out if it's written as r1c2468.

Finally, some people like to shorten the ALS to (5=7). I realize that shortening is a goal, but this saves only three characters and makes it more difficult for this particular reader to follow along.

I'd welcome the comments of others.