`THTMLPageProducer`
pl	ro	OnWriteHeader
pl	ro	OnWriteVisualHeader
pl	ro	OnWriteVisualBody
pl	ro	OnWriteVisualFooter

`THTMLCustomPageProducer`
pt		OnWriteHeader
pt		OnWriteVisualHeader
pt		OnWriteVisualBody
pt		OnWriteVisualFooter

`THTMLCustomEntityProducer`
pt		OnWriteEntity

`THTMLContentProducer`

`THTTPContentProducer`