Ius scriptum is Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 for "written law". Ius scriptum was the body of statute laws made by the legislature. The laws were known as leges ("laws") and plebiscita ("plebiscites" which came from the Plebeian Council

Plebeian Council

The Concilium Plebis — known in English as the Plebeian Council or People's Assembly — was the principal popular assembly of the ancient Roman Republic. It functioned as a legislative assembly, through which the plebeians could pass laws, elect magistrates, and try judicial cases. The Plebeian...

). Roman lawyers would also include in the ius scriptum:

• The edicts of magistrates (magistratuum edicta),
• The advice of the Senate (Senatus consulta),
• The responses and thoughts of jurists (responsa
  Responsa
  Responsa comprise a body of written decisions and rulings given by legal scholars in response to questions addressed to them.-In the Roman Empire:Roman law recognised responsa prudentium, i.e...
  
   prudentium), and
• The proclamations and beliefs of the emperor (principum placita).

Ius scriptum was contrasted with ius non scriptum

Ius non scriptum

Ius non scriptum is Latin for "unwritten law". It contrasts with the ius scriptum by way of their sources . The ius non scriptum was the body of common laws that arose from customary practice. It had become binding over time....

, the body of common laws that arose from customary practice and had become binding over time.