In the distribution I use, the tasks are listed in the task list by default (at least for Java). For other content types, you may check the following settings.
Display the Tasks View: Window > Show View > Other > General > Tasks
For non-Java Task Tags: check the following settings: Window > Preferences > General > Editors > Structured Text Editors > Task Tags You can enable searching for task tags in the [Task Tags] tab and select the content types in the [Filters] tab.
For Java task tags, you should look in: Window > Preferences > Java > Compiler > Task Tags
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