CREATE TABLE characteristics (characteristic_id DECIMAL, characteristic_type_code TEXT, characteristic_data_type TEXT, characteristic_name TEXT, other_characteristic_details TEXT)
CREATE TABLE product_characteristics (product_id DECIMAL, characteristic_id DECIMAL, product_characteristic_value TEXT)
CREATE TABLE ref_colors (color_code TEXT, color_description TEXT)
CREATE TABLE ref_product_categories (product_category_code TEXT, product_category_description TEXT, unit_of_measure TEXT)
CREATE TABLE products (product_id DECIMAL, color_code TEXT, product_category_code TEXT, product_name TEXT, typical_buying_price TEXT, typical_selling_price TEXT, product_description TEXT, other_product_details TEXT)
CREATE TABLE ref_characteristic_types (characteristic_type_code TEXT, characteristic_type_description TEXT)

Find the category descriptions of the products whose descriptions include letter 't'.
SELECT T1.product_category_description FROM ref_product_categories AS T1 JOIN products AS T2 ON T1.product_category_code = T2.product_category_code WHERE T2.product_description LIKE '%t%'
SELECT "T1"."product_category_description" FROM "ref_product_categories" AS "T1" JOIN "products" AS "T2" ON "T1"."product_category_code" = "T2"."product_category_code" AND "T2"."product_description" LIKE '%t%'