In order to facilitate page-kind-specific stylesheet overrides, the body element on each generated page should define a class that is specific to the kind of page.

It is suggested to use class names similar to and derived fromthe names used in the recent generator meta tag.

The set of names there is:
AllClassesIndexWriter
AllPackagesIndexWriter
AnnotationTypeWriterImpl
ClassUseWriter
ClassWriterImpl
ConstantsSummaryWriterImpl
DeprecatedListWriter
DocFileWriter
HelpWriter
IndexRedirectWriter
ModuleIndexWriter
ModuleWriterImpl
PackageTreeWriter
PackageUseWriter
PackageWriterImpl
SerializedFormWriterImpl
SplitIndexWriter
TreeWriter

I suggest dropping "Writer" and "Impl", converting the name to lower-case, and using "-" to separate words. That suggests the following names:

all-classes-index
all-packages-index
annotation-type
class-use
class
constants-summary
deprecated-list
doc-file
help
index-redirect
module-index
module
package-tree
package-use
package
serialized-form
split-index
tree

It might also be worth appending "-declaration" to the names "module", "package", "class".

It's an impl-quirk, that should be fixed eventually, that annotation types are handled separately from other types (JDK-8181506). For example, classes, interfaces and enums are all similar enough to be generated by a single writer. We should not perpetuate the quirk in the set of class names.