Inserting code from external site

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What's the safest & best way to insert some html from a different site? I wish to have some links at the bottom of the home pages of several sites,the links being 'sourced' from one single place to save constant updating.

I know there are security issues so perhaps it's a question of taking advice from hosting company.

I was initially planning on calling a remote .js file via entering code through an html block.

Advice?

thanks.