It depends on what you are specifying. We use the quality and workmanship requirements of D1.1 regardless of the grade of steel. The WPS is written specifically for the materials and process.

Please see AWS D1.1 :2004 C1.2 Limitations(2nd and 3rd sentence)
Basically it is left up to the EOR if the base material is outside of the scope of D1.1.
This gives some insight to the code writer's intentions.
Refer to 4.7.3 for steels not listed in Table 3.1 or Annex M.
Prequalified procedures can not be used because of paragraph 3.14 due to the material being over 50ksi min yield.
just a few thoughts,
John Wright

John is right in that 4130 is not specifically addressed in D1.1 so the EOR must evaluate whether D1.1 criteria are applicable.

To more directly answer the first part of your question, it means grades of steel that are required to have 100,000 psi minimum yield strength. ASTM A514 is one example (100ksi minimum yield for thicknesses 2-1/2" and less).
To contrast the other end, A36 is required to have a 36ksi minimum yield strength.

Chet Guilford