I don’t want any feedback on why I want Old Norse, I just want to know if it can be done.
Since the Seal of Biliteracy is for any student who masters academic English and "any other language" (according to the FAQ), it is possible in theory to get a Seal of Biliteracy for English and Old Norse.
However, the State of Illinois or the school where you study needs to have implemented or recognised criteria or a language certificate for Old Norse. The Seal of Biliteracy website has samples of criteria from several schools in California. The Illinois State Seal of Biliteracy has a list of assessments in English and other languages; this list does not mention an assessment for Old Norse. According to the document about other assessments, a " school district that chooses to use an assessment to measure foreign language proficiency that is not included on the list shall maintain evidence that the assessment meets the following criteria:"
- “Standardized assessment” is one that is available for use on a statewide or national basis and meets generally accepted standards of fairness, validity and reliability as stated in “Standards for Educational and Psychological Testing” (2013), published by the American Educational Research Association, and
- “Intermediate high” as defined by the ACTFL Proficiency Guidelines 2012, published by the American Council on the Teaching of Foreign Languages; or for the American Sign Language, “intermediate high” is equivalent to meeting progress indicators for grade 12 set forth in the Standards for Learning American Sign Language (2014), published by the American Sign Language Teachers Association.
So all depends on the existence of such an assessment for Old Norse and the school district's willingness to recognise it.
However, a school district "may choose to also award the State Seal of Biliteracy through an alternative evidence method". Since an assessment that meets the above criteria is unlikely to exist, the way forward is to convince the school and/or the school district to adopt an "alternative evidence method" for Old Norse.