When sorting file names, `ls` ignores characters like `-,_`. I expected it to use those characters in sorting as well. 

An example:

```
touch a1 a2 a-1 a-2 a_1 a_2 a.1 a.2 a,1 a,2

```

Now display these files with `ls -1`:

```
a1
a_1
a-1
a,1
a.1
a2
a_2
a-2
a,2
a.2

```

What I expected was something like this:

```
a1
a2
a,1
a,2
a.1
a.2
a_1
a_2
a-1
a-2

```

i.e. I expected the non-alphanumeric characters to be taken into account when sorting. 

Can anyone explain this behaviour? Is this behaviour mandated by a standard? Or is this due the encoding being UTF-8? 

**Update:** It seems that this is related to UTF-8 sorting:

```
$ LC_COLLATE=C ls -1
a,1
a,2
a-1
a-2
a.1
a.2
a1
a2
a_1
a_2

```