The contents of this page will be posted soon; in the meantime here are some interesting quotations. Before those, however, you might like to consider, regardless of the contents of writing, some questions.
The court roll of the Merton College manor of Barkby (Leics.) in the summer of 1289 recorded the following in the context of general disputes between the customary tenants and the new lord, Merton College, and in a plea of land:

Quia Inquisicio dicit quod de assensu omnium tenencium fecerunt
unam literam falsam ad dominam de Ros nomine Ricardi de sancto Johanne
In absentia sua ideo omnes In misericordia Et quia Willelmus Ernald 
clericus scripsit literam predictam
[marginal note] amerciamentum illud taxatur ad voluntatem domine de Ros
[Notes: Richard de Sancto Johanne was the College's steward; William Ernald belonged to a local family of customary tenants, the Ernalds.]

Item prepositus quia negauit literam quam fecit Custodi pro Johanne
Ernald et Christiana uxore sua ut patet in cedula pendente in rotulo Ideo
in misericordia plegii Willelmus pleytur et Radulphus Bercarius

Inquisicio dicit quod non fuerunt ad assensum nec consensum faciendi
literam in qua continebatur quod Christiana quondam filia Hereberti 
non proposuit nec voluit terram que fuit predicti Hereberti et hoc contra
voluntatem Roggeri fratris sui ... quod Roggerus filius Hereberti perfecit
literam istam sponte [sic] et non per consensum tenentium nostrorum nec per 
assensum prepositi  Ideo dictus Roggerus in misericordia plegii Willelmus
Daleby Henricus Bonde Radulphus Franceys Roggerus filius Hereberti [sic]

In this case, an earlier entry explains the issue:
Radulphus filius Hereberti custumarius dominorum est mortuus ideo terra
et tenementa sua capiantur in manu dominorum et venit Roggerus filius et
heres dicti Radulphi et petiebat hereditatem patris sui et Jus secundum
consuetudinem manerii et quia senescallus inuenit quod Johannes Ernald et
Christiana soror eiusdem Roggeri habuerunt ingressum in dicto tenemento
per custodem ponitur in Respectum usque senescallus habuerit colloquium 
cum dicto Custode saluis dominis .xx.s. pro ingressu ...

[The Custos is the Warden of Merton College.]
Note not only the use of written instruments in this issue, but also the use of the notion of inheritance of customary [villein] lands conceded in the College's language in its rolls.

[Merton College, Oxford, Merton Muniments -- if you are interested, ask for the reference]