Credits for principal actors in opening or closing sequence — contractually binding. Placement, size, and duration are negotiated points.
The placement of your lead actors in the opening or closing credits is not simply a formal obligation—it is a highly political instrument. Who gets starring, in what size, in what position in the title sequence or roll, is negotiated by agents with bleeding gums. This is money, fame, future salaries. An A-list star will not accept their name being visible for a second longer than a co-star. This is stipulated in the contract—points for name size, duration of appearance, whether alone on screen or shared.
On set, you notice little of this, but in marketing and post-production, it becomes real. The opening credits or the end crawl must precisely match the contracts. Some stars demand a single card—their name alone on a black background, not shared. Others get shared cards because their budget doesn't allow for it. The font size, the duration of the appearance, whether in the first or second row of the credits—everything is calculated and fixed in millimeters or frame count. The editor and the title designer work according to a strict catalog provided by production management from the legal department.
Practically, this can become a problem: a star with a big name may have to be placed less prominently than before during a renegotiation, and this becomes a political issue. Even with ensembles where ten actors are equal, you need a clear hierarchy. The names must appear in identical size, identical duration, identical layout—otherwise, there will be trouble with the agents. This is not creative leeway; it is contract fulfillment. And it is controlled: every major distributor requires a certificate of compliance for the final credits before the DCP is released.