diff --git a/anki.d b/anki.d
index 4714fe2..0c06022 100755
Binary files a/anki.d and b/anki.d differ
diff --git a/main.go b/main.go
index a2bbb38..c8808b6 100644
--- a/main.go
+++ b/main.go
@@ -13,30 +13,35 @@ import (
 
 type (
 	DB interface {
-		HistoryOf(string) map[string][]History
-		Next(string, string) time.Time
-		Question(string) Question
-		LastAnswer(string, string) (string, Answer)
-		Answer(string) Answer
-		PushAnswer(string, string, string, bool) error
+		HistoryOf(IDU) map[IDQ][]History
+		Next(IDU, IDQ) time.Time
+		Question(IDQ) Question
+		LastAnswer(IDU, IDQ) (IDA, Answer)
+		Answer(IDA) Answer
+		PushAnswer(IDU, IDQ, Renderable, bool) error
 		Close()
 	}
 	Question struct {
-		Q     string
-		Clues []string
-		Tags  []string
+		Q     Renderable
+		Clues []Renderable
+		Tags  []IDT
 	}
 	Answer struct {
-		Q      string
-		A      string
+		Q      IDQ
+		A      Renderable
 		TS     int64
-		Author string
+		Author IDU
 	}
 	History struct {
-		A    string
+		A    IDA
 		TS   int64
 		Pass bool
 	}
+	IDA        string
+	IDQ        string
+	IDU        string
+	IDT        string
+	Renderable string
 )
 
 func main() {
@@ -51,14 +56,14 @@ func Main() error {
 		return err
 	}
 	defer db.Close()
-	user := os.Getenv("USER")
+	user := IDU(os.Getenv("USER"))
 	for q, _ := range db.HistoryOf(user) {
 		if time.Until(db.Next(user, q)) > 0 {
 			continue
 		}
 		question := db.Question(q)
 		fmt.Printf("> Q: ")
-		if strings.HasPrefix(question.Q, "img:") {
+		if strings.HasPrefix(string(question.Q), "img:") {
 		} else {
 			fmt.Printf("%s", question.Q)
 		}
@@ -90,11 +95,11 @@ func Main() error {
 		switch readline() {
 		case "s":
 		case "n":
-			if err := db.PushAnswer(user, q, response, false); err != nil {
+			if err := db.PushAnswer(user, q, Renderable(response), false); err != nil {
 				return err
 			}
 		default:
-			if err := db.PushAnswer(user, q, response, true); err != nil {
+			if err := db.PushAnswer(user, q, Renderable(response), true); err != nil {
 				return err
 			}
 		}
@@ -117,7 +122,7 @@ func NewDB() (DB, error) {
 	return newYamlDB(os.Getenv("DB"))
 }
 
-func (q Question) Tagged(tag string) bool {
+func (q Question) Tagged(tag IDT) bool {
 	for i := range q.Tags {
 		if q.Tags[i] == tag {
 			return true
diff --git a/yamldb.go b/yamldb.go
index 263c344..6c29d3e 100644
--- a/yamldb.go
+++ b/yamldb.go
@@ -12,19 +12,19 @@ type (
 	yamlDB struct {
 		addr      string
 		Knowledge knowledge
-		Users     map[string]user
+		Users     map[IDU]user
 		Cadence   []duration
 	}
 	knowledge struct {
-		Questions map[string]Question
-		Answers   map[string]Answer
+		Questions map[IDQ]Question
+		Answers   map[IDA]Answer
 	}
 	user struct {
 		Tags    tags
-		History map[string][]History
+		History map[IDQ][]History
 	}
 	tags struct {
-		Assignments []string
+		Assignments []IDT
 	}
 )
 
@@ -32,10 +32,10 @@ func newYamlDB(p string) (yamlDB, error) {
 	db := yamlDB{
 		addr: p,
 		Knowledge: knowledge{
-			Questions: map[string]Question{},
-			Answers:   map[string]Answer{},
+			Questions: map[IDQ]Question{},
+			Answers:   map[IDA]Answer{},
 		},
-		Users:   map[string]user{},
+		Users:   map[IDU]user{},
 		Cadence: []duration{},
 	}
 	if b, err := os.ReadFile(p); err != nil {
@@ -62,8 +62,8 @@ func (db yamlDB) Close() {
 	}
 }
 
-func (db yamlDB) HistoryOf(user string) map[string][]History {
-	result := map[string][]History{}
+func (db yamlDB) HistoryOf(user IDU) map[IDQ][]History {
+	result := map[IDQ][]History{}
 	for k, v := range db.Users[user].History {
 		result[k] = append([]History{}, v...)
 	}
@@ -77,7 +77,7 @@ func (db yamlDB) HistoryOf(user string) map[string][]History {
 	return result
 }
 
-func (db yamlDB) Next(user, q string) time.Time {
+func (db yamlDB) Next(user IDU, q IDQ) time.Time {
 	history := db.Users[user].History[q]
 	progress := 0
 	for i := range history {
@@ -95,12 +95,12 @@ func (db yamlDB) Next(user, q string) time.Time {
 	return db.lastTS(user, q).Add(time.Duration(db.Cadence[progress]))
 }
 
-func (db yamlDB) Question(q string) Question {
+func (db yamlDB) Question(q IDQ) Question {
 	return db.Knowledge.Questions[q]
 }
 
-func (db yamlDB) LastAnswer(user, q string) (string, Answer) {
-	maxk := ""
+func (db yamlDB) LastAnswer(user IDU, q IDQ) (IDA, Answer) {
+	var maxk IDA
 	var maxv Answer
 	for k, v := range db.Knowledge.Answers {
 		if v.Q == q && v.Author == user {
@@ -113,12 +113,12 @@ func (db yamlDB) LastAnswer(user, q string) (string, Answer) {
 	return maxk, maxv
 }
 
-func (db yamlDB) Answer(a string) Answer {
+func (db yamlDB) Answer(a IDA) Answer {
 	return db.Knowledge.Answers[a]
 }
 
-func (db yamlDB) PushAnswer(user, q, a string, pass bool) error {
-	uuid := uuid.New().String()
+func (db yamlDB) PushAnswer(user IDU, q IDQ, a Renderable, pass bool) error {
+	uuid := IDA(uuid.New().String())
 	db.Knowledge.Answers[uuid] = Answer{
 		Q:      q,
 		A:      a,
@@ -133,7 +133,7 @@ func (db yamlDB) PushAnswer(user, q, a string, pass bool) error {
 	return nil
 }
 
-func (db yamlDB) lastTS(user, q string) time.Time {
+func (db yamlDB) lastTS(user IDU, q IDQ) time.Time {
 	max := int64(0)
 	for _, v := range db.Users[user].History[q] {
 		if v.TS > max {