Could you explain the phrase: “marriage invalid…disparity nul”?
On the back of a baptismal certificate there are notions for the reception of other sacraments. It will note First Communion and Confirmation if the parish has records of those. When a Catholic is married in the Church a notice is sent out to the person’s parish of baptism and a notation is made on their baptismal record. The notion includes the parish and date of marriage.
When a marriage is declared null by a tribunal a notice also goes out to the parish of baptism so that they can note the declaration of nullity.
Based on the information you’ve provided it appears that the individual was previously married and it has been declared null.