CREATE TABLE table_203_202 (id NUMBER, "network" CLOB, "company" CLOB, "mobile prefixes" CLOB, "mobile examples" CLOB, "landline prefixes" CLOB, "landline examples" CLOB, "notes" CLOB)

there are no landline prefixes for what 4 companies ?
SELECT "network" FROM table_203_202 WHERE "landline prefixes" IS NULL
SELECT "network" FROM "table_203_202" WHERE "landline prefixes" IS NULL