A purity pledge/vow is a promise and vow made by an individual to God, and to a future spouse. The individual promises to stay pure until after marriage.
There are several different kinds and types of purity pledges/vows. Some vows/pledges are very detailed and long; often including witnesses and additional promises made by daughters to their fathers and fathers to their daughters. While other vows/pledges are very short and simple; the vow/pledge is made by simply signing a paper.
It really just depends on an individual’s preference and dedication to the vow/pledge. The intensity of the purity pledges/vows should be determined by the individual who is making the vow/promise. It should meet and reflect the individual’s motivation and desire. After all, a decision to stay pure until marriage is essentially made by an individual and no one else.