1. Introduction
Formalism, as a literary school, emerged under the influence of post-Saussurean linguistics, whose aim was to demonstrate the literariness (literarité) of a literary text. Formalists identified literariness, defamiliarization, and foregrounding in texts through two main mechanisms: deviation (norm-breaking) and parallelism (rule-enhancement). From their perspective, in the first type, the poet can distinguish poetic language from standard language by employing techniques such as phonological deviation and others.
In Makhzan al-Asrar, Nezami, and in Tohfat al-Ahrar, Jami have succeeded in employing phonological deviation strategies—namely deletion, substitution, addition, assimilation, easing (takhfif), and reduction (taskin)—to strengthen the musicality and metrical structure of their poetry and to achieve defamiliarization and literariness in the text. Therefore, examining these two works and demonstrating the importance of the poets’ attention to the application of these techniques, as well as identifying their frequency of use, is of significant importance.
Accordingly, in this study, through examples of verses, it is investigated to what extent the use of components such as deletion, substitution, reduction, easing, assimilation, and gemination has been effective in maintaining metrical balance and in harmonizing rhyme words in these two works.

2. Methodology
This research employs a descriptive–analytical method based on library research. Two works—Makhzan al-Asrar by Nezami and Tohfat al-Ahrar by Jami—have been examined with regard to phonological deviation components.

3. Discussion
Saturation: Saturation refers to the transformation of one of the short vowels [a, e, o] into its corresponding long vowel (cf. Mohseni & Sorahti, 2009: 8). In Tohfat al-Ahrar, it is used in only eight words: in one case, the short vowel [a] in the middle of a word is changed into the long vowel [ā]; in four cases, the short vowel [a] in the prefix na- is changed into [ā]; and in two cases, the short vowel [o] is changed into the long vowel [u].
Examples:
دامن (دامان)
سر ز گریبان وفــا بر زدم دست به دامان دعا در زدم (Jami, 1378: 492)

نشده (ناشده)
ناشده اقلیم دوام و ثبات تنگ بر ایشان ز حدود و جهات (ibid.: 470)
افکند (اوفکند)
باز به حالش پی دفع گزند تابشی از «تابَ عَلَیْه» اوفکند (ibid.: 501)

4. Conclusion
In phonological deviation, the technique of “deletion” shows the highest frequency: in Makhzan al-Asrar 483 cases (40.47%), and in Tohfat al-Ahrar 306 cases (45.88%), making it the most frequent among phonological devices.
The technique of “assimilation” appears in Makhzan al-Asrar with 275 cases (26.99%) and in Tohfat al-Ahrar with 199 cases (29.83%), while the technique of “reduction” occurs with 206 cases (20.21%) in Makhzan al-Asrar and 114 cases (17.09%) in Tohfat al-Ahrar, showing significant usage.
The technique of “easing” appears in Tohfat al-Ahrar with 25 cases (3.74%), while in Makhzan al-Asrar, despite having two subtypes of this technique, it occurs 40 times (3.93%).
Nezami employs the technique of “substitution” in five cases (0.45%), while Jami uses it in twelve cases (1.80%).
The “saturation” technique is used solely for maintaining musicality and meter in Nezami’s work in five cases (0.45%) and in Jami’s work in eight cases (1.20%).

The technique of “gemination” also appears in Makhzan al-Asrar in five cases (0.45%) and in Tohfat al-Ahrar in three cases (0.45%) among the total phonological deviation strategies.