Represents a link from one issue to another. When an issue that's being imported contains a link to another issue, this link is imported as a temporary string at first. This approach ensures that links to issues that are not imported yet are not lost. When import is finished, temporary strings are replaced with ordinary references to existing issues when possible.
The name of the link.
The type of the link.
The target entity that the link points to.
The type of the custom field.