So I was curious about the limit on number called up in POTUS' latest EO re activating special reserve. See "Presidential…." below

Mobilization of Reserve:

>>Individual service members, portions of units, or entire units of the reserve components may be called into active duty (also referred to as mobilized, activated, or called up), under several conditions:

>>Full Mobilization (10 USC 12301(a)) requires a declaration of war or national emergency by the United States Congress, affects all reservists (including those on inactive status and retired reserve members), and may last until six months after the war or emergency for which it was declared.

>>Partial Mobilization (10 USC 12302) requires a declaration of national emergency, affects only the Ready Reserve, and is limited to a maximum of one million personnel activated for no more than two years.

>>Presidential Reserve Call-Ups (10 USC 12304) do not require a declaration of national emergency but do require the President to notify Congress, and is limited to 200,000 Selected Reservists and 30,000 Individual Ready Reservists for up to 270 days.

>>Military Reserve Emergency Activation (10 USC 12304a) allows the SecDef to activate the Ready Reserves (minus the Guard) in response to major disasters or emergencies for up to 120 days.