Why is IN written before Salford on signs around the Salford area?

I am an ex Salfordian, moving to Lincolnshire and then Yorkshire. Last time I visited my parents (still living in Salford) I noticed that many signs at the side of the road had IN before Salford, also Salford Reds rugby team have IN Salford on their shirts. Why?

i think is something to do with all the re-development that is going on in salford an also means of what you can do IN salford

hope thts right?

rugby reds vs bulls