Usage with custom size (live template)

edit
|size= value {{flag}} output {{flaglist}} output
10px
x8px
10x8px
35px
x25px
35x25px

Usage with custom size (sandbox template)

edit
|size= value {{flag}} output {{flaglist/sandbox}} output
10px
x8px
10x8px
35px
x25px
35x25px