0 to choose to be part of an activity, arrangement, etc.:
1 the fact of choosing to take part in an activity, arrangement, etc. rather than being forced to take part:
2 to choose to be part of an activity, arrangement, etc.:
3 the fact that you do not have, receive, or join in something unless you choose to, or something that you do not have or receive unless you choose it:
Users have to click to give the company permission to collect data about their online habits, a process called opt-in.
We have a company pensions policy where there is an opt-in instead of an opt-out.
opt-in feature/system/policy The social networking site has introduced an opt-in feature for customers.
The patient is offered the opportunity to participate ("opt-in") in various programs offered by the pharmacy, such as e-mail prescription refill reminders.
Other countries continue this pattern of differences between opt-out and opt-in systems.
The whole idea of opt-in has been put forward as the solution to end spam.
Here, and in most other countries, the opt-in principle applies before an organ of a deceased person can be used.
While less debated that the opt-in for solicited commercial e-mail, similar issues are at stake for proposed harmonised opt-in regarding directories.
The opt-in regime is one uniform legal solution.
How on earth does he expect an opt-in electorate to work?
Some issues cannot easily be accommodated in the context of a regulatory system, even if that is an opt-in system.
