It is specifically a dictionary of Scots, or Lallans, which some scholars consider merely a dialect of English and others a distinct language rooted in Old English.
( It ( ( ( is specifically ) ( ( ( ( a dictionary ) ( of Scots ) ) ( , ( or ( Lallans , ) ) ) ) ( which ( ( some scholars ) ( consider ( ( ( merely ( a dialect ) ) ( of ( ( English and ) others ) ) ) ( ( a ( distinct language ) ) ( rooted ( in ( Old English ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (PRP It)) (VP (VBZ is) (ADVP (RB specifically)) (NP (NP (NP (DT a) (NN dictionary)) (PP (IN of) (NP (NNP Scots)))) (PRN (, ,) (CC or) (NP (NNP Lallans)) (, ,)) (SBAR (WHNP (WDT which)) (S (NP (DT some) (NNS scholars)) (VP (VBP consider) (S (NP (NP (RB merely) (DT a) (NN dialect)) (PP (IN of) (NP (NP (NNP English)) (CC and) (NP (NNS others))))) (NP (NP (DT a) (JJ distinct) (NN language)) (VP (VBN rooted) (PP (IN in) (NP (NNP Old) (NNP English))))))))))) (. .)))
Scots is its own language, it is not an English dialect. 
( ( Scots ( is ( its ( own language ) ) ) ) ( , ( it ( ( ( is not ) ( an ( English dialect ) ) ) . ) ) ) )
(ROOT (S (S (NP (NNS Scots)) (VP (VBZ is) (NP (PRP$ its) (JJ own) (NN language)))) (, ,) (NP (PRP it)) (VP (VBZ is) (RB not) (NP (DT an) (JJ English) (NN dialect))) (. .)))