Within your villages, there are two ways to be promoted. The first option is to have your Kage recognize your deeds and promote you in character at their discretion. The second is to complete a list of criteria listed below in order to apply for promotion from them. This eases the process of promotions, as Kage will not need to micro-manage every one of their shinobi's promotion paths, and the characters themselves gain a specific set of goals to strive for to reach their promotion.
To be promoted to Chuunin, you need to obtain 800 Field CP, and complete a minimum of six missions, with at least one of your missions being a C-Rank or higher.
To be promoted to Tokubetsu Jounin, you need a Specialist in a Fighting Style or a Masterful Stat in addition to already being a Chuunin. Aside from that, you need to obtain 1,000 CP from C-Rank or above missions, with at least one B-Rank or higher mission completed.
To be promoted to Jounin from Tokubetsu Jounin, you need 1,600 Field CP acquired from C-Rank or above missions, with at least one B-Rank or higher mission being completed. As well, 600 of that Field CP must come from PC Missions. If you wish to skip from Chuunin straight to Jounin, 2,600 Field CP is required instead.
To be promoted to ANBU, you should qualify for Jounin (or already be one), and you must obtain 1,200 Field CP from PC missions. The PC missions completed will be judged at the update request to ensure that they were of a quality worthy of promotion.
What is "Field CP"?
Field CP is counted as any CP earned while completing a mission for your village or while engaged in serious conflict for your village(such as defending against a foreign invasion). Field CP is kept track of independently from the rest of your CP values, and is used solely to track progression along these promotions.
When Field CP is gained, it still counts as normal CP and follows all normal CP rules(I.E., it goes into your UCP total, impacts your TCP total, etc.).
Exceptions to the Appellate Promotions
While this system allows for more systematic promotions, the Kage of a village still holds authority over the promotions given within the village. A Kage is allowed to dictate which of these ranks can be promoted into via appeal, and which ranks are excluded so that they can handle those promotions personally. In the case of ranks that are allowed to be appealed into, Kage are able to "blacklist" certain members of their village in order to exclude them temporarily from ranking up through this system. This is normally done when a character has committed questionable acts and has lost some of the village's trust in them.