## Stripping disallowed attributes by `(insert|delete)Content` [#1088](https://github.com/ckeditor/ckeditor5-engine/issues/1088) ### Simple scenario. 1. Copy a paragraph with italic and link. 2. Paste it to the Heading 1. Inserted text should be stripped 3. Paste it to the Heading 2. Inserted text should be a link only. 4. Paste it to paragraph. Inserted text should not be stripped. ### Simple scenario (element). 1. Copy image. 2. Paste it to the editor. Image should be inserted with an alternative text "Sample image". ### Nested nodes. 1. Copy a list item with bold and link. 2. Paste it into the empty block (directly to the root) . Inserted list item should be a bold link. 2. Paste it into the empty block in BlockQuote. Inserted list item should be a bold only. ### Auto paragraphing. 1. Copy a text with bold. 2. Select all content in the editor. 3. Paste copied text. Inserted content should be a paragraph and should be stripped from bold. ### Auto paragraphing (disallowed block). 1. Copy Heading 3 with bold and italic. 2. Select all content in the editor. 3. Paste copied text. Inserted content should be a paragraph and should be stripped from bold.