Comment 23 for bug 1429030

>The netboot installer is not the same thing as the mini.iso. The download
>page refers to "Network installer". Nowhere does it reference the mini.iso,
>which is clearly not being booted over the network.

If this is true, then the documentation is confusing.

The "network installer" links take you to a netboot page and from there you choose which architechure you're using. The mini.iso file resides inside this netboot subdirectory.

So, it's not surprising that someone might think that "network installer" and "netboot" are the same.

To make it clear about this:
1) Go to https://ubuntu.com/download/alternative-downloads
2) Click on of the "Download the network installer for (x)" links
3) This will then take you the netboot page. Ex: 19.04 link -> http://cdimage.ubuntu.com/netboot/19.04/
4) Now, you click on the architechure you want. I'll show for amd64

You'll see a listing of files like:
[ICO] Name Last modified Size
[PARENTDIR] Parent Directory -
[ ] boot.img.gz 2019-04-16 08:24 55M
[ ] ldlinux.c32 2019-04-16 08:24 113K
[ ] mini.iso 2019-04-16 08:24 68M
[ ] netboot.tar.gz 2019-04-16 08:24 55M
[ ] pxelinux.0 2019-04-16 08:24 41K
[DIR] pxelinux.cfg/ 2019-04-16 08:24 -
[DIR] ubuntu-installer/ 2019-04-16 08:24 -
[DIR] xen/ 2019-04-16 08:24 -

So, again network installer -> netboot -> netboot-ARCH-subdir -> mini.iso