'F' or other similar, abbreviations etc meant to follow posts are disallowed because they are not in line with normal social behaviour and when taken in an offline context, are not acceptable. We do not walk up to people in the real world and say 'F' and walk away. We make conversation, ask questions etc and then ask the person to please share the recipe. It doesn't take much longer to say a few words or just click the post menu and choose the option to receive notifications from the post.