Thanks to Chris Sutton who, via a comment, has supplied some ISSNs (Magazine International Standard Serial numbers, needed to claim ALCS).
For Woman's Weekly the ISSN is 00437417
For Woman's Weekly Fiction Specials it's 23997508
For My Weekly, it's 0262026X
For My Weekly Fiction Specials it's 14790475
And for The Weekly News it's 02623714 (This is now considered a newspaper and not eligible for ALCS.)
ISSNs are usually displayed somewhere in the magazine, although it's often hard to find them. If you can't and you have work in a particular mag, you could email the fiction editor and ask them for that magazine's ISSN.
From Bernadette –
Take a Break Fiction Feast is 09530983
People's Friend is 02622382
Writing Magazine is 09649166
From Glenda Young
The People's Friend Fiction Special 14790469
ISSNs are often found in the bar codes, if you know how to interpret them.
If anyone adds other ISSNs and mentions them in the comments, then I'll add them to this post, hopefully providing a useful resource for us all.
Btw, I was really pleased this morning to see 13 new comments on this blog – until I realised every single one was spam! The spam is a bit annoying. Genuine comments are really appreciated. Whether they're asking questions, providing answers, encouraging me or others, even just a bit of chat, I value them all.