Let
D
D
be a complete discrete valuation domain with the unique maximal ideal
p
{\mathfrak {p}}
. We suppose that
D
D
is an algebra over an algebraically closed field
K
K
and
D
/
p
≅
K
D/{\mathfrak {p}} \cong K
. Subamalgam
D
D
-suborders
Λ
∙
\Lambda ^{\bullet }
of a tiled
D
D
-order
Λ
\Lambda
are studied in the paper by means of the integral Tits quadratic form
q
Λ
∙
:
Z
n
1
+
2
n
3
+
2
⟶
Z
q_{\Lambda ^{\bullet }}: {\mathbb {Z}}^{n_{1}+2n_{3}+2 } \,\,\longrightarrow {\mathbb {Z}}
. A criterion for a subamalgam
D
D
-order
Λ
∙
\Lambda ^{\bullet }
to be of tame lattice type is given in terms of the Tits quadratic form
q
Λ
∙
q_{{\Lambda ^{\bullet }}}
and a forbidden list
Ω
1
,
…
,
Ω
17
\Omega _{1},\ldots ,\Omega _{17}
of minor
D
D
-suborders of
Λ
∙
\Lambda ^{\bullet }
presented in the tables.