If you are not comfortable with the rules for applying then ignore it, because each campaign manager has their own way of marketing.
And in my opinion, the rule is stated to see the seriousness of the applicant, because usually there are members who like to move from one campaign to another and usually to get a higher payment, so by using the signature code it shows that they are serious.
However, for that signature campaign it seems that it will only get applicants who are free because the value is not high.
If all users are like this, it's not surprising we would see these kind requirement in the future.
1. User must wear avatar and signature, if you're currently in a campaign, you need to gamble to leave the present in order to join the new one.
2. Submit your CV, tell what you're good at, write good post on ANN thread and praise the manager.
3. Like, comment, and share every post in social medias.
4. User must not jump into another campaign less than 3 months, otherwise you will blacklisted for the next 3 campaigns.
5. Accepted user agree the first 100 posts will not be paid in order to know the naturally of your post.
These all ridiculous rules just for a sake of "seriousness", please distinguish between "seriousness" and "slavery".