Admissibility of evidence depends on whether the proposed fact, if proved, would be relevant. Where admissibility requires proof of a foundational fact, that fact must ordinarily be established first, unless the Court accepts an undertaking for subsequent proof. Where relevance depends on another fact, the Judge may control the order of proof by permitting the dependent evidence first or requiring prior proof of the foundational fact.

Order of production and examination of witnesses is governed by the law and prevailing practice applicable to civil and criminal procedure. Where no such procedural law or practice regulates the sequence, the Court has discretion to determine the order in which witnesses are produced and examined.

Section 134 removes any fixed numerical requirement for witness testimony in proving a fact. No prescribed minimum number of witnesses is mandatory in any case, and proof may be established without a compulsory numerical threshold for witness evidence.

An accomplice is a competent witness against an accused person. A conviction founded solely on uncorroborated accomplice testimony is not illegal merely because independent corroboration is absent. The provision recognises the evidentiary competence of accomplices and does not impose corroboration as a condition of a legally valid conviction.

Section 132 requires a witness to answer relevant questions in civil or criminal proceedings even where an answer may incriminate the witness or expose the witness to a penalty or forfeiture. A compelled answer cannot subject the witness to arrest or prosecution, nor may it be proved against the witness in criminal proceedings, except in a prosecution for giving false evidence through that answer.

Section 131 preserves derivative evidentiary privilege by barring compelled production of documents in a person's possession or electronic records under that person's control when another person could refuse their production if they possessed or controlled them. Compulsion is permitted only where that other person consents to production. The protection follows the entitlement to withhold the material rather than the identity of its current holder or controller.

A witness who is not a party to a suit cannot be compelled to produce title deeds relating to property, documents evidencing property held as pledgee or mortgagee, or documents whose production may tend to incriminate the witness. Compulsion is permitted only where the witness has agreed in writing with the person seeking production, or a person through whom that person claims, to produce the deeds or documents.

Confidential communications with a legal professional adviser cannot ordinarily be compelled before a court. Where a person offers himself or herself as a witness, disclosure may be required only for communications necessary to explain evidence already given. Other confidential communications remain protected.

Reassessment proceedings initiated through a notice and an authorising order under Section 148A(d) fell outside the applicable statutory limitation period. Under the governing principle for reassessment limitation, both the notice and the Section 148A(d) order were invalid as time-barred. As limitation disposed of the validity issue, separate examination of other challenges was unnecessary.

Section 128 preserves professional privilege where a party gives evidence in a suit, as this does not constitute consent to disclose communications protected under section 126. When a party calls a barrister, pleader, attorney or vakil as a witness, consent extends only to matters on which that legal professional is questioned and which would otherwise remain undisclosable.

Section 127 applies the provisions of section 126 to interpreters and to the clerks or servants of barristers, pleaders, attorneys and vakils. The application extends beyond the listed legal practitioners themselves to persons identified by the provision as interpreters or as their clerks or servants. Each identified category is brought within the scope of section 126 by reason of that specified function or employment.

Professional communications between a client and a legal professional are protected from disclosure without the client's express consent, including employment-related communications, documents learned through employment, and advice given to the client. Protection continues after the engagement ends. Privilege does not cover communications made in furtherance of an illegal purpose or facts observed during employment showing a crime or fraud committed after employment commenced.

Source confidentiality prevents compelled disclosure by magistrates and police officers of persons or sources from whom offence information was obtained. Revenue officers receive the same protection for information relating to offences against public revenue. A revenue officer includes every officer employed in or about the business of any branch of public revenue.

Section 124 protects official communications made to a public officer in official confidence. A public officer cannot be compelled to disclose them where the officer considers that disclosure would harm public interests. Protection applies to communications received officially and depends on the concerned officer's assessment that public-interest prejudice would result from disclosure.

Evidence derived from unpublished official records concerning affairs of State cannot be given unless permission is obtained from the officer heading the relevant department. The departmental head may grant or withhold permission at discretion, thereby regulating disclosure and evidentiary use of State-related material held in unpublished official records, including material maintained in official departmental custody and linked to governmental affairs.

Marital communications cannot be compelled from a current or former spouse and cannot be voluntarily disclosed without the communicator's consent or that of the communicator's representative in interest. The protection is excluded in proceedings between married persons and in prosecutions concerning a crime committed by one spouse against the other.

Judges and Magistrates cannot be compelled to answer questions about their judicial conduct or matters learned in court while acting in that capacity, unless a subordinate court issues a special order. They may, however, be examined regarding other events that occurred in their presence while acting judicially. Questions concerning an allegedly improper deposition or statements made before a Magistrate require a superior court's special order.

In every civil proceeding, each party to the suit and the husband or wife of any party is competent to testify. In criminal proceedings against a person, that person's husband or wife is likewise competent to testify. The rule treats marital status as no bar to competency in these proceedings.

Evidence of a witness unable to speak may be conveyed through intelligible writing or signs made in open court and is deemed oral evidence. Where the witness cannot communicate verbally, the court must use an interpreter or special educator to record the statement and must videograph that statement.

Competency to testify extends to all persons unless tender years, extreme old age, bodily or mental disease, or a comparable cause prevents understanding questions or giving rational answers. Mental illness alone does not disqualify a witness; disqualification depends on impaired comprehension and inability to respond rationally.